diff --git a/Contrib/Banner/Banner.c b/Contrib/Banner/Banner.c
index a391f906..3f69a6b2 100644
--- a/Contrib/Banner/Banner.c
+++ b/Contrib/Banner/Banner.c
@@ -11,7 +11,7 @@ BOOL bFailed;
 
 TCHAR buf[1024];
 
-BOOL CALLBACK BannerProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK BannerProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if (uMsg == WM_INITDIALOG)
   {
@@ -42,7 +42,7 @@ BOOL CALLBACK BannerProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
   {
     DestroyWindow(hwndDlg);
   }
-  return 0;
+  return FALSE;
 }
 
 BOOL ProcessMessages()
diff --git a/Contrib/ExDLL/pluginapi.c b/Contrib/ExDLL/pluginapi.c
index 370f1561..5d878606 100644
--- a/Contrib/ExDLL/pluginapi.c
+++ b/Contrib/ExDLL/pluginapi.c
@@ -46,7 +46,7 @@ void NSISCALL pushstring(const TCHAR *str)
   *g_stacktop=th;
 }
 
-TCHAR * NSISCALL getuservariable(const int varnum)
+TCHAR* NSISCALL getuservariable(const int varnum)
 {
   if (varnum < 0 || varnum >= __INST_LAST) return NULL;
   return g_variables+varnum*g_stringsize;
@@ -159,9 +159,9 @@ void NSISCALL SetUserVariableW(const int varnum, const wchar_t* wideStr)
 
 // playing with integers
 
-int NSISCALL myatoi(const TCHAR *s)
+INT_PTR NSISCALL nsishelper_str_to_ptr(const TCHAR *s)
 {
-  int v=0;
+  INT_PTR v=0;
   if (*s == _T('0') && (s[1] == _T('x') || s[1] == _T('X')))
   {
     s++;
@@ -204,7 +204,7 @@ int NSISCALL myatoi(const TCHAR *s)
   return v;
 }
 
-unsigned NSISCALL myatou(const TCHAR *s)
+unsigned int NSISCALL myatou(const TCHAR *s)
 {
   unsigned int v=0;
 
@@ -270,13 +270,12 @@ int NSISCALL myatoi_or(const TCHAR *s)
   return v;
 }
 
-int NSISCALL popint()
+INT_PTR NSISCALL popintptr()
 {
   TCHAR buf[128];
   if (popstringn(buf,COUNTOF(buf)))
     return 0;
-
-  return myatoi(buf);
+  return nsishelper_str_to_ptr(buf);
 }
 
 int NSISCALL popint_or()
@@ -284,13 +283,12 @@ int NSISCALL popint_or()
   TCHAR buf[128];
   if (popstringn(buf,COUNTOF(buf)))
     return 0;
-
   return myatoi_or(buf);
 }
 
-void NSISCALL pushint(int value)
+void NSISCALL pushintptr(INT_PTR value)
 {
-	TCHAR buffer[1024];
-	wsprintf(buffer, _T("%d"), value);
+	TCHAR buffer[30];
+	wsprintf(buffer, sizeof(void*) > 4 ? _T("%Id") : _T("%d"), value);
 	pushstring(buffer);
 }
diff --git a/Contrib/ExDLL/pluginapi.h b/Contrib/ExDLL/pluginapi.h
index e762bbfc..d6541123 100644
--- a/Contrib/ExDLL/pluginapi.h
+++ b/Contrib/ExDLL/pluginapi.h
@@ -56,16 +56,19 @@ extern unsigned int g_stringsize;
 extern stack_t **g_stacktop;
 extern TCHAR *g_variables;
 
+void NSISCALL pushstring(const TCHAR *str);
+void NSISCALL pushintptr(INT_PTR value);
+#define pushint(v) pushintptr((INT_PTR)(v))
 int NSISCALL popstring(TCHAR *str); // 0 on success, 1 on empty stack
 int NSISCALL popstringn(TCHAR *str, int maxlen); // with length limit, pass 0 for g_stringsize
-int NSISCALL popint(); // pops an integer
+INT_PTR NSISCALL popintptr();
+#define popint() ( (int) popintptr() )
 int NSISCALL popint_or(); // with support for or'ing (2|4|8)
-int NSISCALL myatoi(const TCHAR *s); // converts a string to an integer
-unsigned NSISCALL myatou(const TCHAR *s); // converts a string to an unsigned integer, decimal only
+INT_PTR NSISCALL nsishelper_str_to_ptr(const TCHAR *s);
+#define myatoi(s) ( (int) nsishelper_str_to_ptr(s) ) // converts a string to an integer
+unsigned int NSISCALL myatou(const TCHAR *s); // converts a string to an unsigned integer, decimal only
 int NSISCALL myatoi_or(const TCHAR *s); // with support for or'ing (2|4|8)
-void NSISCALL pushstring(const TCHAR *str);
-void NSISCALL pushint(int value);
-TCHAR * NSISCALL getuservariable(const int varnum);
+TCHAR* NSISCALL getuservariable(const int varnum);
 void NSISCALL setuservariable(const int varnum, const TCHAR *var);
 
 #ifdef _UNICODE
diff --git a/Contrib/LangDLL/LangDLL.c b/Contrib/LangDLL/LangDLL.c
index 52192930..c9d02f0e 100644
--- a/Contrib/LangDLL/LangDLL.c
+++ b/Contrib/LangDLL/LangDLL.c
@@ -32,7 +32,7 @@ struct lang {
   UINT cp;
 } *langs;
 
-BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   int i, size;
   TCHAR *selected_language = NULL;
diff --git a/Contrib/MakeLangId/MakeLangId.cpp b/Contrib/MakeLangId/MakeLangId.cpp
index 876b3719..c9403ad5 100644
--- a/Contrib/MakeLangId/MakeLangId.cpp
+++ b/Contrib/MakeLangId/MakeLangId.cpp
@@ -193,7 +193,7 @@ line sub[] = {
 	CBL(SUBLANG_UZBEK_CYRILLIC)
 };
 
-BOOL CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
+INT_PTR CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
 	size_t i;
 	switch (uMsg) {
 	case WM_INITDIALOG:
@@ -222,7 +222,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
 				TCHAR *lang_id = (TCHAR *)GlobalLock(hMem);
 				wsprintf(lang_id, _T("%u"), MAKELANGID(primary[SendDlgItemMessage(hwndDlg, IDC_PRIMARY, CB_GETCURSEL, 0, 0)].id, sub[SendDlgItemMessage(hwndDlg, IDC_SUB, CB_GETCURSEL, 0, 0)].id));
 				GlobalUnlock(hMem);
-				if (!OpenClipboard(hwndDlg)) return 0;
+				if (!OpenClipboard(hwndDlg)) return FALSE;
 				EmptyClipboard();
 #ifdef _UNICODE
 				SetClipboardData(CF_UNICODETEXT,hMem);
@@ -234,7 +234,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
 		}
 		break;
 	}
-	return 0;
+	return FALSE;
 }
 
 NSIS_ENTRYPOINT_GUINOCRT
diff --git a/Contrib/Makensisw/jnetlib/httpget.cpp b/Contrib/Makensisw/jnetlib/httpget.cpp
index bc692151..0989fa5d 100644
--- a/Contrib/Makensisw/jnetlib/httpget.cpp
+++ b/Contrib/Makensisw/jnetlib/httpget.cpp
@@ -16,7 +16,7 @@
 #include "util.h"
 #include "httpget.h"
 
-void *operator new( unsigned int num_bytes ){return GlobalAlloc(GPTR,num_bytes);}
+void *operator new( size_t num_bytes ){return GlobalAlloc(GPTR,num_bytes);}
 void operator delete( void *p ) { if (p) GlobalFree(p); }
 
 JNL_HTTPGet::JNL_HTTPGet(JNL_AsyncDNS *dns, int recvbufsize, char *proxy)
diff --git a/Contrib/Makensisw/makensisw.xml b/Contrib/Makensisw/makensisw.xml
index 69aa6811..2a36de38 100644
--- a/Contrib/Makensisw/makensisw.xml
+++ b/Contrib/Makensisw/makensisw.xml
@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
-<assemblyIdentity version="1.0.0.0" processorArchitecture="X86" name="Nullsoft.NSIS.makensisw" type="win32"/>
+<assemblyIdentity version="1.0.0.0" processorArchitecture="*" name="Nullsoft.NSIS.makensisw" type="win32"/>
 <description>MakeNSIS Wrapper</description>
 <dependency>
 <dependentAssembly>
-<assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="X86" publicKeyToken="6595b64144ccf1df" language="*" />
+<assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" />
 </dependentAssembly>
 </dependency>
 <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
diff --git a/Contrib/NSISdl/nsisdl.cpp b/Contrib/NSISdl/nsisdl.cpp
index 206c9da5..1aa31cf7 100644
--- a/Contrib/NSISdl/nsisdl.cpp
+++ b/Contrib/NSISdl/nsisdl.cpp
@@ -30,7 +30,7 @@
 
 #include <nsis/pluginapi.h> // nsis plugin
 
-void *operator new( unsigned int num_bytes )
+void *operator new( size_t num_bytes )
 {
   return GlobalAlloc(GPTR,num_bytes);
 }
diff --git a/Contrib/StartMenu/StartMenu.c b/Contrib/StartMenu/StartMenu.c
index bda5d9bc..4a3a7e3d 100644
--- a/Contrib/StartMenu/StartMenu.c
+++ b/Contrib/StartMenu/StartMenu.c
@@ -25,8 +25,8 @@ WNDPROC lpWndProcOld;
 
 void (__stdcall *validate_filename)(TCHAR *);
 
-BOOL CALLBACK dlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
-static BOOL CALLBACK ParentWndProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+INT_PTR CALLBACK dlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK ParentWndProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
 void AddFolderFromReg(int nFolder);
 
 static UINT_PTR PluginCallback(enum NSPIM msg)
@@ -158,9 +158,9 @@ void __declspec(dllexport) Select(HWND hwndParent, int string_size, TCHAR *varia
   }
 }
 
-static BOOL CALLBACK ParentWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK ParentWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
-  BOOL bRes = CallWindowProc(lpWndProcOld,hwnd,message,wParam,lParam);
+  INT_PTR bRes = CallWindowProc(lpWndProcOld,hwnd,message,wParam,lParam);
   if (message == WM_NOTIFY_OUTER_NEXT && !bRes)
   {
     // if leave function didn't abort (lRes != 0 in that case)
@@ -191,7 +191,7 @@ void AddRTLStyle(HWND hWnd, long dwStyle)
    \
   y_offset += cy + 3;
 
-BOOL CALLBACK dlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK dlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   HWND hwLocation = GetDlgItem(hwndDlg, IDC_LOCATION);
   HWND hwDirList = GetDlgItem(hwndDlg, IDC_DIRLIST);
@@ -424,7 +424,7 @@ BOOL CALLBACK dlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       return SendMessage(hwParent, uMsg, wParam, lParam);
     break;
   }
-	return 0;
+  return FALSE;
 }
 
 BOOL WINAPI DllMain(HINSTANCE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
diff --git a/Contrib/System/SConscript b/Contrib/System/SConscript
index bf14a27c..3ce52ac9 100644
--- a/Contrib/System/SConscript
+++ b/Contrib/System/SConscript
@@ -26,14 +26,17 @@ docs = Split("""
 
 Import('BuildPlugin env')
 
-conf = env.Configure()
-if conf.TryCompile('END', '.S'):
-	files += ['Source/Call.S']
-elif conf.TryCompile('.end', '.sx'):
-	files += ['Source/Call.sx']
+if env['TARGET_ARCH'] != 'amd64':
+	conf = env.Configure()
+	if conf.TryCompile('END', '.S'):
+		files += ['Source/Call.S']
+	elif conf.TryCompile('.end', '.sx'):
+		files += ['Source/Call.sx']
+	else:
+		print 'WARNING: unable to find assembler for Call.S'
+	conf.Finish()
 else:
-	print 'WARNING: unable to find assembler for Call.S'
-conf.Finish()
+	print 'WARNING: missing Win64 code, dynamic function calls not supported'
 
 BuildPlugin(
 	target,
diff --git a/Contrib/System/Source/Buffers.c b/Contrib/System/Source/Buffers.c
index 5f066352..ab9d3fbc 100644
--- a/Contrib/System/Source/Buffers.c
+++ b/Contrib/System/Source/Buffers.c
@@ -15,8 +15,8 @@ TempStack *tempstack = NULL;
 
 static void AllocWorker(unsigned int mult)
 {
-    int size;
-    if ((size = popint()) == 0)
+    size_t size;
+    if ((size = popintptr()) == 0)
     {
         system_pushint(0);
         return;
@@ -56,7 +56,7 @@ PLUGINFUNCTIONSHORT(Copy)
     // Ok, check the size
     if (size == 0) size = (SIZE_T) GlobalSize(source);
     // and the destinantion
-    if ((int) dest == 0) 
+    if (!dest) 
     {
         dest = GlobalAlloc((GPTR), size);
         system_pushintptr((INT_PTR) dest);
diff --git a/Contrib/System/Source/Plugin.c b/Contrib/System/Source/Plugin.c
index 212110c6..f4d8f636 100644
--- a/Contrib/System/Source/Plugin.c
+++ b/Contrib/System/Source/Plugin.c
@@ -134,20 +134,20 @@ void myitoa64(__int64 i, TCHAR *buffer)
     *buffer = 0;
 }
 
-int system_popint()
+INT_PTR system_popintptr()
 {
-    int value;
+    INT_PTR value;
     TCHAR *str;
     if ((str = system_popstring()) == NULL) return -1;
-    value = myatoi(str);
+    value = StrToIntPtr(str);
     GlobalFree(str);
     return value;
 }
 
-void system_pushint(int value)
+void system_pushintptr(INT_PTR value)
 {
-    TCHAR buffer[80];
-    wsprintf(buffer, _T("%d"), value);
+    TCHAR buffer[50];
+    wsprintf(buffer, sizeof(void*) > 4 ? _T("%Id") : _T("%d"), value);
     system_pushstring(buffer);
 }
 
diff --git a/Contrib/System/Source/Plugin.h b/Contrib/System/Source/Plugin.h
index a06fc08d..a7a98849 100644
--- a/Contrib/System/Source/Plugin.h
+++ b/Contrib/System/Source/Plugin.h
@@ -5,15 +5,17 @@
 
 // Always use system* functions to keep the size down
 #define pushstring error(use system_pushstring)
+#undef pushint
 #define pushint error(use system_pushint)
+#define pushintptr error(use system_pushintptr)
 
-#define popint system_popint
+#undef myatoi
 #define myatoi(str) ( (int) myatoi64(str) ) 
+#define system_pushint(v) system_pushintptr((INT_PTR)(v))
+#define popintptr system_popintptr
 #ifdef _WIN64
-#	error TODO
+#	define StrToIntPtr(str) ( (INT_PTR)myatoi64((str)) )
 #else
-#	define system_pushintptr system_pushint
-#	define popintptr popint
 #	define StrToIntPtr(str) ( (INT_PTR)myatoi((str)) )
 #endif
 
@@ -39,8 +41,8 @@ extern TCHAR *system_setuservariable(int varnum, TCHAR *var);
 extern TCHAR* system_popstring();  // NULL - stack empty
 extern TCHAR* system_pushstring(TCHAR *str);
 extern __int64 myatoi64(TCHAR *s);
-extern int system_popint();  // -1 -> stack empty
-extern void system_pushint(int value);
+extern INT_PTR system_popintptr();  // -1 -> stack empty
+extern void system_pushintptr(INT_PTR value);
 
 extern HANDLE GlobalCopy(HANDLE Old);
 extern void *copymem(void *output, void *input, size_t cbSize);
diff --git a/Contrib/System/Source/System.c b/Contrib/System/Source/System.c
index 5b085fdd..ddf4e110 100644
--- a/Contrib/System/Source/System.c
+++ b/Contrib/System/Source/System.c
@@ -30,18 +30,18 @@
 #define PCD_PARAMS  2
 #define PCD_DONE    3   // Just Continue
 
+const int PARAMSIZEBYTYPE_PTR = (4==sizeof(void*)) ? 1 : 2;
 const int ParamSizeByType[7] = {
-    0, // PAT_VOID (Size will be equal to 1)
+    0, // PAT_VOID (Size will be equal to 1) //BUGBUG64?
     1, // PAT_INT
     2, // PAT_LONG
-    1, // PAT_STRING
-    1, // PAT_WSTRING
-    1, // PAT_GUID
+    sizeof(void*) / 4, // PAT_STRING //BUGBUG64?
+    sizeof(void*) / 4, // PAT_WSTRING //BUGBUG64?
+    sizeof(void*) / 4, // PAT_GUID //BUGBUG64?
     0}; // PAT_CALLBACK (Size will be equal to 1) //BUGBUG64?
-const int PARAMSIZEBYTYPE_PTR = (4==sizeof(void*)) ? 1 : 2;
 
 // Thomas needs to look at this.
-const int ByteSizeByType[7] = {
+static const int ByteSizeByType[7] = {
     1, // PAT_VOID
     1, // PAT_INT
     1, // PAT_LONG
@@ -55,7 +55,7 @@ int LastStackReal;
 DWORD LastError;
 volatile SystemProc *LastProc;
 int CallbackIndex;
-CallbackThunk* CallbackThunkListHead;
+CallbackThunk* g_CallbackThunkListHead;
 HINSTANCE g_hInstance;
 
 // Return to callback caller with stack restore
@@ -145,7 +145,7 @@ PLUGINFUNCTION(Debug)
             GetLocalTime(&t);
             GetTimeFormat(LOCALE_SYSTEM_DEFAULT, LOCALE_NOUSEROVERRIDE, &t, NULL, buftime, 1024);
             GetDateFormat(LOCALE_SYSTEM_DEFAULT, LOCALE_NOUSEROVERRIDE, &t, NULL, bufdate, 1024);
-            wsprintf(buffer, _T("System, %s %s [build ") __TTIME__ _T(" ") __TDATE__ _T("]\n"), buftime, bufdate);
+            wsprintf(buffer, _T("System, %s %s [build %hs %hs]\n"), buftime, bufdate, __TIME__, __DATE__);
             WriteToLog(buffer);
         } else ;
     else
@@ -207,9 +207,9 @@ PLUGINFUNCTIONSHORT(Free)
 {
     HANDLE memtofree = (HANDLE)popintptr();
 
-    if (CallbackThunkListHead)
+    if (g_CallbackThunkListHead)
     {
-        CallbackThunk *pCb=CallbackThunkListHead,*pPrev=NULL;
+        CallbackThunk *pCb=g_CallbackThunkListHead,*pPrev=NULL;
         do 
         {
             if (GetAssociatedSysProcFromCallbackThunkPtr(pCb) == (SystemProc*)memtofree) 
@@ -217,7 +217,7 @@ PLUGINFUNCTIONSHORT(Free)
                 if (pPrev)
                     pPrev->pNext=pCb->pNext;
                 else
-                    CallbackThunkListHead=pCb->pNext;
+                    g_CallbackThunkListHead=pCb->pNext;
 
                 --(CallbackIndex);
                 VirtualFree(pCb,0,MEM_RELEASE);
@@ -268,12 +268,45 @@ PLUGINFUNCTION(Get)
     }
 } PLUGINFUNCTIONEND
 
+
+#ifdef _WIN64
+/*
+TODO: CallProc/Back not implemeted.
+Fake the behavior of the System plugin for the LoadImage API function so MUI works.
+BUGBUG: Leaking DeleteObject and failing GetClientRect
+*/
+static SystemProc* CallProc(SystemProc *proc)
+{
+    INT_PTR ret, *place;
+    LastError = lstrcmp(proc->ProcName, sizeof(TCHAR) > 1 ? _T("LoadImageW") : _T("LoadImageA"));
+    if (!LastError)
+    {
+        ret = (INT_PTR) LoadImage((HINSTANCE)proc->Params[1].Value,
+          (LPCTSTR)proc->Params[2].Value, (UINT)proc->Params[3].Value,
+          (int)proc->Params[4].Value, (int)proc->Params[5].Value,
+          (UINT)proc->Params[6].Value);
+        LastError = GetLastError();
+    }
+    else
+        proc->ProcResult = PR_ERROR, ret = 0;
+    place = (INT_PTR*) proc->Params[0].Value;
+    if (proc->Params[0].Option != -1) place = (INT_PTR*) &(proc->Params[0].Value);
+    if (place) *place = ret;
+    return proc;
+}
+static SystemProc* CallBack(SystemProc *proc)
+{
+    proc->ProcResult = PR_ERROR;
+    return proc;
+}
+#endif
+
+
 PLUGINFUNCTION(Call)
 {
     // Prepare input
     SystemProc *proc = PrepareProc(TRUE);
-    if (proc == NULL)
-      return;
+    if (proc == NULL) return;
 
     SYSTEM_LOG_ADD(_T("Call "));
     SYSTEM_LOG_ADD(proc->DllName);
@@ -281,8 +314,7 @@ PLUGINFUNCTION(Call)
     SYSTEM_LOG_ADD(proc->ProcName);
     //SYSTEM_LOG_ADD(_T("\n"));
     SYSTEM_LOG_POST;
-    if (proc->ProcResult != PR_CALLBACK)
-        ParamAllocate(proc);
+    if (proc->ProcResult != PR_CALLBACK) ParamAllocate(proc);
     ParamsIn(proc);
 
     // Make the call
@@ -308,35 +340,30 @@ PLUGINFUNCTION(Call)
         // Always return flag set - return separate return and result
         ParamsOut(proc);
         GlobalFree(system_pushstring(GetResultStr(proc)));
-    } else
+    }
+    else
     {
         if (proc->ProcResult != PR_OK)
         {
-            ProcParameter pp;
-            // Save old return param
-            pp = proc->Params[0];
+            ProcParameter pp = proc->Params[0]; // Save old return param
 
             // Return result instead of return value
-            proc->Params[0].Value = BUGBUG64(int) GetResultStr(proc);
+            proc->Params[0].Value = (INT_PTR) GetResultStr(proc);
             proc->Params[0].Type = PAT_TSTRING;
-            // Return all params
-            ParamsOut(proc);
 
-            // Restore old return param
-            proc->Params[0] = pp;
-        } else 
+            ParamsOut(proc); // Return all params
+            proc->Params[0] = pp; // Restore old return param
+        }
+        else
             ParamsOut(proc);        
     }
 
     if (proc->ProcResult != PR_CALLBACK)
     {
-        // Deallocate params if not callback
         ParamsDeAllocate(proc);
 
         // if not callback - check for unload library option
-        if ((proc->Options & POPT_UNLOAD) 
-            && (proc->ProcType == PT_PROC) 
-            && (proc->Dll != NULL)) 
+        if ((proc->Options & POPT_UNLOAD) && proc->ProcType == PT_PROC && proc->Dll)
             FreeLibrary(proc->Dll); // and unload it :)
 
         // In case of POPT_ERROR - first pop will be proc error
@@ -344,8 +371,7 @@ PLUGINFUNCTION(Call)
     }    
 
     // If proc is permanent?
-    if ((proc->Options & POPT_PERMANENT) == 0)
-        GlobalFree((HANDLE) proc); // No, free it
+    if ((proc->Options & POPT_PERMANENT) == 0) GlobalFree((HANDLE) proc); // No, free it
 } PLUGINFUNCTIONEND
 
 PLUGINFUNCTIONSHORT(Int64Op)
@@ -602,13 +628,14 @@ SystemProc *PrepareProc(BOOL NeedForCall)
             case _T('v'):
             case _T('V'): temp2 = PAT_VOID; break;
 
-            #if !defined(SYSTEM_X86)
-                #error "TODO: handle p"
-            #else
-                case _T('p'):
-            #endif
+#ifndef _WIN64
+            case _T('p'):
+#endif
             case _T('i'):
             case _T('I'): temp2 = PAT_INT; break;
+#ifdef _WIN64
+            case _T('p'):
+#endif
             case _T('l'):
             case _T('L'): temp2 = PAT_LONG; break;
             case _T('m'):
@@ -865,12 +892,9 @@ SystemProc *PrepareProc(BOOL NeedForCall)
 void ParamAllocate(SystemProc *proc)
 {
     int i;
-
     for (i = 0; i <= proc->ParamCount; i++)
-        if (((HANDLE) proc->Params[i].Value == NULL) && (proc->Params[i].Option == -1))
-        {
-            proc->Params[i].Value = BUGBUG64(int) GlobalAlloc(GPTR, 4*ParamSizeByType[proc->Params[i].Type]);
-        }
+        if (!proc->Params[i].Value && proc->Params[i].Option == -1)
+            proc->Params[i].Value = (INT_PTR) GlobalAlloc(GPTR, 4*ParamSizeByType[proc->Params[i].Type]);
 }
 
 void ParamsIn(SystemProc *proc)
@@ -958,7 +982,7 @@ void ParamsIn(SystemProc *proc)
 #ifdef SYSTEM_LOG_DEBUG
         {
             TCHAR buf[666];
-            wsprintf(buf, _T("\t\t\tParam In %d:    type %d value 0x%08X value2 0x%08X"), i, 
+            wsprintf(buf, _T("\t\t\tParam In %d:    type %d value ")SYSFMT_HEXPTR _T(" value2 0x%08X"), i, 
                 par->Type, par->Value, par->_value);
             SYSTEM_LOG_ADD(buf);
             SYSTEM_LOG_POST;
@@ -974,18 +998,18 @@ void ParamsIn(SystemProc *proc)
 void ParamsDeAllocate(SystemProc *proc)
 {
     int i;
-
     for (i = proc->ParamCount; i >= 0; i--)
-        if (((HANDLE) proc->Params[i].Value != NULL) && (proc->Params[i].Option == -1))
+        if (proc->Params[i].Value && proc->Params[i].Option == -1)
         {
             GlobalFree((HANDLE) (proc->Params[i].Value));
-            proc->Params[i].Value = (int) NULL;
+            proc->Params[i].Value = 0;
         }
 }
 
 void ParamsOut(SystemProc *proc)
 {
-    int i, *place;
+    INT_PTR *place;
+    int i;
     TCHAR *realbuf;
     LPWSTR wstr;
 
@@ -993,8 +1017,8 @@ void ParamsOut(SystemProc *proc)
     do
     {
         // Retreive pointer to place
-        if (proc->Params[i].Option == -1) place = BUGBUG64(int*) proc->Params[i].Value;
-        else place = BUGBUG64(int*) &(proc->Params[i].Value);
+        if (proc->Params[i].Option == -1) place = (INT_PTR*) proc->Params[i].Value;
+        else place = (INT_PTR*) &(proc->Params[i].Value);
 
         realbuf = AllocString();
 
@@ -1005,7 +1029,7 @@ void ParamsOut(SystemProc *proc)
             lstrcpy(realbuf,_T(""));
             break;
         case PAT_INT:
-            wsprintf(realbuf, _T("%d"), *((int*) place));
+            wsprintf(realbuf, _T("%d"), (int)(*((INT_PTR*) place)));
             break;
         case PAT_LONG:
             myitoa64(*((__int64*) place), realbuf);
@@ -1038,7 +1062,7 @@ void ParamsOut(SystemProc *proc)
 #endif
             break;
         case PAT_CALLBACK:
-            wsprintf(realbuf, _T("%d"), proc->Params[i].Value);
+            wsprintf(realbuf, _T("%d"), BUGBUG64(proc->Params[i].Value));
             break;
         }
 
@@ -1083,6 +1107,9 @@ void ParamsOut(SystemProc *proc)
 
 HANDLE CreateCallback(SystemProc *cbproc)
 {
+#ifdef SYSTEM_X64
+    return BUGBUG64(HANDLE) NULL;
+#else
     char *mem;
 
     if (cbproc->Proc == NULL)
@@ -1093,8 +1120,8 @@ HANDLE CreateCallback(SystemProc *cbproc)
 
         mem = (char *) (cbproc->Proc = VirtualAlloc(NULL, sizeof(CallbackThunk), MEM_COMMIT, PAGE_EXECUTE_READWRITE));
 
-        ((CallbackThunk*)mem)->pNext=CallbackThunkListHead;
-        CallbackThunkListHead=(CallbackThunk*)mem;
+        ((CallbackThunk*)mem)->pNext=g_CallbackThunkListHead;
+        g_CallbackThunkListHead=(CallbackThunk*)mem;
 
 #ifdef SYSTEM_X86
         *(mem++) = (char) 0xB8; // Mov eax, const
@@ -1111,6 +1138,7 @@ HANDLE CreateCallback(SystemProc *cbproc)
 
     // Return proc address
     return cbproc->Proc;
+#endif
 }
 
 void CallStruct(SystemProc *proc)
@@ -1215,7 +1243,7 @@ void CallStruct(SystemProc *proc)
     SYSTEM_LOG_POST;
 
     // Proc virtual return - pointer to memory struct
-    proc->Params[0].Value = (int) proc->Proc;
+    proc->Params[0].Value = BUGBUG64(int) proc->Proc;
 }
 
 /*
@@ -1231,25 +1259,28 @@ the same means as used for the _RPT0 macro. This leads to an endless recursion.
 
 BOOL WINAPI DllMain(HINSTANCE hInst, DWORD fdwReason, LPVOID lpReserved)
 {
-        g_hInstance=hInst;
-        
-        if (DLL_PROCESS_ATTACH == fdwReason)
-        {
-            // change the protection of return command
-            VirtualProtect(&retexpr, sizeof(retexpr), PAGE_EXECUTE_READWRITE, (PDWORD)&LastStackPlace);
+    g_hInstance=hInst;
 
-            // initialize some variables
-            LastStackPlace = 0;
-            LastStackReal = 0;
-            LastError = 0;
-            LastProc = NULL;
-            CallbackIndex = 0;
-            CallbackThunkListHead = NULL;
-            retexpr[0] = (char) 0xC2;
-            retexpr[2] = 0x00;
-        }
+    if (DLL_PROCESS_ATTACH == fdwReason)
+    {
+        // change the protection of return command
+        VirtualProtect(&retexpr, sizeof(retexpr), PAGE_EXECUTE_READWRITE, (PDWORD)&LastStackPlace);
 
-        return TRUE;
+        // initialize some variables
+        LastStackPlace = 0, LastStackReal = 0;
+        LastError = 0;
+        LastProc = NULL;
+        CallbackIndex = 0, g_CallbackThunkListHead = NULL;
+#ifdef SYSTEM_X86
+        retexpr[0] = (char) 0xC2;
+        retexpr[2] = 0x00;
+#elif defined(SYSTEM_X64)
+        retexpr[0] = BUGBUG64(0);
+#else
+#error TODO
+#endif
+    }
+    return TRUE;
 }
 
 /*
diff --git a/Contrib/System/Source/System.h b/Contrib/System/Source/System.h
index f65953fd..9527f7e3 100644
--- a/Contrib/System/Source/System.h
+++ b/Contrib/System/Source/System.h
@@ -10,7 +10,11 @@
 #else
 #    error "Unknown architecture!"
 #endif
-
+#ifdef _WIN64
+#define SYSFMT_HEXPTR _T("0x%016IX")
+#else
+#define SYSFMT_HEXPTR _T("0x%08X")
+#endif
 
 
 // The following ifdef block is the standard way of creating macros which make exporting 
@@ -76,8 +80,8 @@ typedef struct
 {
     int Type;
     int Option; // -1 -> Pointer, 1-... -> Special+1
-    int Value;  // it can hold any 4 byte value BUGBUG: What about pointers on Win64?
-    int _value; // value buffer for structures > 4 bytes (I hope 8 bytes will be enough)
+    INT_PTR Value; // it can hold any pointer sized value
+    int _value; // value buffer for structures > 4 bytes (I hope 8 bytes will be enough) BUGBUG: Does Win64 need this?
     int Size; // Value real size (should be either 1 or 2 (the number of pushes))
     int Input; //BUGBUG: What about pointers on Win64?
     int Output;
@@ -119,6 +123,8 @@ struct tag_CallbackThunk
         #pragma pack(pop)
         */
         char asm_code[10];
+    #elif defined(SYSTEM_X64)
+        char asm_code[BUGBUG64(1)]; // TODO: BUGBUG64
     #else
         #error "Asm thunk not implemeted for this architecture!"
     #endif
@@ -129,6 +135,8 @@ struct tag_CallbackThunk
 // Free() only knows about pNext in CallbackThunk, it does not know anything about the assembly, that is where this helper comes in...
 #ifdef SYSTEM_X86
 #   define GetAssociatedSysProcFromCallbackThunkPtr(pCbT) ( (SystemProc*)  *(unsigned int*) (((char*)(pCbT))+1) )
+#elif defined(SYSTEM_X64)
+#   define GetAssociatedSysProcFromCallbackThunkPtr(pCbT) BUGBUG64(NULL)
 #else
 #   error "GetAssociatedSysProcFromCallbackThunkPtr not defined for the current architecture!"
 #endif
diff --git a/Contrib/System/System.nsh b/Contrib/System/System.nsh
index 86df4734..f8098419 100644
--- a/Contrib/System/System.nsh
+++ b/Contrib/System/System.nsh
@@ -14,105 +14,105 @@
 ; ------------- Functions --------------
 
 ; LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
-!define sysWNDPROC "(i.s, i.s, i.s, i.s) iss"
+!define sysWNDPROC "(p.s, i.s, p.s, p.s) pss"
 
 ; LRESULT DefWindowProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
-!define sysDefWindowProc "user32::DefWindowProc(i, i, i, i) i"
+!define sysDefWindowProc "user32::DefWindowProc(p, i, p, p) p"
 
-!define sysMessageBox "user32::MessageBox(i, t, t, i) i"
+!define sysMessageBox "user32::MessageBox(p, t, t, i) i"
 
 !define sysMessageBeep "user32::MessageBeep(i) i"
 
-!define sysMessageBoxIndirect 'user32::MessageBoxIndirect(i) i'
+!define sysMessageBoxIndirect 'user32::MessageBoxIndirect(p) i'
 
 ; HMODULE GetModuleHandle(LPCTSTR lpModuleName); 
 !define sysGetModuleHandle "kernel32::GetModuleHandle(t) i"
 
 ; HMODULE LoadLibrary(LPCTSTR lpFileName);
-!define sysLoadLibrary "kernel32::LoadLibrary(t) i"
+!define sysLoadLibrary "kernel32::LoadLibrary(t) p"
 
 ; BOOL FreeLibrary(HMODULE hModule);
-!define sysFreeLibrary "kernel32::FreeLibrary(i) i"
+!define sysFreeLibrary "kernel32::FreeLibrary(p) i"
 
 ; HCURSOR LoadCursor(HINSTANCE hInstance, LPCTSTR lpCursorName);
-!define sysLoadCursor "user32::LoadCursor(i, t) i"
+!define sysLoadCursor "user32::LoadCursor(p, t) p"
 
 ; ATOM RegisterClass(CONST WNDCLASS *lpWndClass);
-!define sysRegisterClass "user32::RegisterClass(i) i"
+!define sysRegisterClass "user32::RegisterClass(p) i"
 
 ; HANDLE LoadImage(HINSTANCE hinst, LPCTSTR lpszName, UINT uType,
 ;       int cxDesired, int cyDesired, UINT fuLoad);
-!define sysLoadImage "user32::LoadImage(i, t, i, i, i, i) i"
+!define sysLoadImage "user32::LoadImage(p, t, i, i, i, i) p"
 
 ; BOOL PlaySound(LPCSTR pszSound, HMODULE hmod, DWORD fdwSound);
-!define sysPlaySound "winmm.dll::PlaySound(t, i, i) i"
+!define sysPlaySound "winmm.dll::PlaySound(t, p, i) i"
 
 ; HWND CreateWindowEx(DWORD dwExStyle, LPCTSTR lpClassName, LPCTSTR lpWindowName,
 ;       DWORD dwStyle, int x, int y, int nWidth, int nHeight, HWND hWndParent,
 ;       HMENU hMenu, HINSTANCE hInstance, LPVOID lpParam);
-!define sysCreateWindowEx "user32::CreateWindowEx(i, t, t, i, i, i, i, i, i, i, i, i) i"
+!define sysCreateWindowEx "user32::CreateWindowEx(i, t, t, i, i, i, i, i, p, p, p, p) p"
 
 ; BOOL IsWindow(HWND hWnd);
-!define sysIsWindow "user32::IsWindow(i) i"
+!define sysIsWindow "user32::IsWindow(p) i"
 
 ; LONG SetWindowLong(HWND hWnd, int nIndex, LONG dwNewLong);
-!define sysSetWindowLong "user32::SetWindowLong(i, i, i) i"
+!define sysSetWindowLong "user32::SetWindowLong(p, i, p) p"
 
 ; BOOL SetWindowPos(HWND hWnd, HWND hWndInsertAfter, int X, int Y, int cx, int cy, UINT uFlags);
-!define sysSetWindowPos "user32::SetWindowPos(i, i, i, i, i, i, i) i"
+!define sysSetWindowPos "user32::SetWindowPos(p, p, i, i, i, i, i) i"
 
 ; BOOL ShowWindow(HWND hWnd, int nCmdShow);
-!define sysShowWindow "user32::ShowWindow(i, i) i"
+!define sysShowWindow "user32::ShowWindow(p, i) i"
 
 ; BOOL DestroyWindow(HWND hWnd);
-!define sysDestroyWindow "user32::DestroyWindow(i) i"
+!define sysDestroyWindow "user32::DestroyWindow(p) i"
 
 ; BOOL GetClientRect(HWND hWnd, LPRECT lpRect);
-!define sysGetClientRect "user32::GetClientRect(i, i) i"
+!define sysGetClientRect "user32::GetClientRect(p, p) i"
 
 ; BOOL GetMessage(LPMSG lpMsg, HWND hWnd, UINT wMsgFilterMin, UINT wMsgFilterMax);
-!define sysGetMessage "user32::GetMessage(i, i, i, i) i"
+!define sysGetMessage "user32::GetMessage(p, p, i, i) i"
 
 ; LRESULT DispatchMessage(CONST MSG *lpmsg);
-!define sysDispatchMessage "user32::DispatchMessage(i) i"
+!define sysDispatchMessage "user32::DispatchMessage(p) p"
 
 ; BOOL DeleteObject(HGDIOBJ hObject);
-!define sysDeleteObject "gdi32::DeleteObject(i) i"
+!define sysDeleteObject "gdi32::DeleteObject(p) i"
 
 ; int GetObject(HGDIOBJ hgdiobj, int cbBuffer, LPVOID lpvObject);
-!define sysGetObject "gdi32::GetObject(i, i, i) i"
+!define sysGetObject "gdi32::GetObject(p, i, p) i"
 
 ; HGDIOBJ SelectObject(HDC hdc, HGDIOBJ hgdiobj);
-!define sysSelectObject "gdi32::SelectObject(i, i) i"
+!define sysSelectObject "gdi32::SelectObject(p, p) p"
 
 ; HDC CreateCompatibleDC(HDC hdc);
-!define sysCreateCompatibleDC "gdi32::CreateCompatibleDC(i) i"
+!define sysCreateCompatibleDC "gdi32::CreateCompatibleDC(p) p"
 
 ; BOOL DeleteDC(HDC hdc);
-!define sysDeleteDC "gdi32::DeleteDC(i) i"
+!define sysDeleteDC "gdi32::DeleteDC(p) i"
 
 ; BOOL BitBlt(HDC hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, 
 ;       HDC hdcSrc, int nXSrc, int nYSrc, DWORD dwRop);
-!define sysBitBlt "gdi32::BitBlt(i, i, i, i, i, i, i, i, i) i"
+!define sysBitBlt "gdi32::BitBlt(p, i, i, i, i, p, i, i, i) i"
 
 ; proposed by abgandar
 ; int AddFontResource(LPCTSTR lpszFilename);
 !define sysAddFontResource "gdi32::AddFontResource(t) i"
 
 ; HDC BeginPaint(HWND hwnd, LPPAINTSTRUCT lpPaint);
-!define sysBeginPaint "user32::BeginPaint(i, i) i"
+!define sysBeginPaint "user32::BeginPaint(p, p) p"
 
 ; BOOL EndPaint(HWND hWnd, CONST PAINTSTRUCT *lpPaint);
-!define sysEndPaint "user32::EndPaint(i, i) i"
+!define sysEndPaint "user32::EndPaint(p, p) i"
 
 ; BOOL SystemParametersInfo(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni);
-!define sysSystemParametersInfo "user32::SystemParametersInfo(i, i, i, i) i"
+!define sysSystemParametersInfo "user32::SystemParametersInfo(i, i, p, i) i"
 
 ; UINT_PTR SetTimer(HWND hWnd, UINT_PTR nIDEvent, UINT uElapse, TIMERPROC lpTimerFunc);
-!define sysSetTimer "user32::SetTimer(i, i, i, k) i"
+!define sysSetTimer "user32::SetTimer(p, p, i, k) i"
 
 ; DWORD GetLogicalDriveStrings(DWORD nBufferLength, LPTSTR LpBuffer);
-!define sysGetLogicalDriveStrings 'kernel32::GetLogicalDriveStrings(i, i) i'
+!define sysGetLogicalDriveStrings 'kernel32::GetLogicalDriveStrings(i, p) i'
 
 !define sysGetDiskFreeSpaceEx 'kernel32::GetDiskFreeSpaceEx(t, *l, *l, *l) i'
 
@@ -120,14 +120,14 @@
 !define sysGetDriveType 'kernel32::GetDriveType(t) i'
 
 ; HANDLE FindFirstFile(LPCTSTR lpFileName,LPWIN32_FIND_DATA lpFindFileData);
-!define sysFindFirstFile 'kernel32::FindFirstFile(t, i) i'
+!define sysFindFirstFile 'kernel32::FindFirstFile(t, p) p'
 
 ; BOOL FindClose(HANDLE hFindFile);
-!define sysFindClose 'kernel32::FindClose(i) i'
+!define sysFindClose 'kernel32::FindClose(p) i'
 
 ; BOOL FileTimeToSystemTime(CONST FILETIME *lpFileTime, 
 ; LPSYSTEMTIME lpSystemTime);
-!define sysFileTimeToSystemTime 'kernel32::FileTimeToSystemTime(*l, i) i'
+!define sysFileTimeToSystemTime 'kernel32::FileTimeToSystemTime(*l, p) i'
 
 ; BOOL FileTimeToLocalFileTime(
 ;       CONST FILETIME *lpFileTime, 
@@ -136,7 +136,7 @@
 
 ; BOOL SystemTimeToTzSpecificLocalTime(LPTIME_ZONE_INFORMATION lpTimeZone, 
 ; LPSYSTEMTIME lpUniversalTime, LPSYSTEMTIME lpLocalTime);
-!define sysSystemTimeToTzSpecificLocalTime 'kernel32::SystemTimeToTzSpecificLocalTime(i, i, i) i'
+!define sysSystemTimeToTzSpecificLocalTime 'kernel32::SystemTimeToTzSpecificLocalTime(p, p, p) i'
 
 !define syslstrlen 'kernel32::lstrlen(t) i'
 
@@ -157,7 +157,7 @@
 ;               LPCTSTR    lpszMenuName; 
 ;               LPCTSTR    lpszClassName; 
 ; } WNDCLASS, *PWNDCLASS; 
-!define stWNDCLASS "(i, k, i, i, i, i, i, i, t, t) i"
+!define stWNDCLASS "(i, k, i, i, p, p, p, p, t, t) p"
 
 ; typedef struct tagMSG {
 ;   HWND   hwnd; 
@@ -167,7 +167,7 @@
 ;   DWORD  time; 
 ;   POINT  pt;  -> will be presented as two separate px and py
 ; } MSG, *PMSG;
-!define stMSG "(i, i, i, i, i, i, i) i"
+!define stMSG "(p, i, p, p, i, i, i) p"
 
 ; typedef struct tagBITMAP {
 ;   LONG   bmType; 
@@ -178,7 +178,7 @@
 ;   WORD   bmBitsPixel; 
 ;   LPVOID bmBits; 
 ; } BITMAP, *PBITMAP; 
-!define stBITMAP "(i, i, i, i, i, i, i) i"
+!define stBITMAP "(i, i, i, i, i, i, p) p"
 
 ; typedef struct _RECT { 
 ;   LONG left; 
@@ -186,7 +186,7 @@
 ;   LONG right; 
 ;   LONG bottom; 
 ; } RECT, *PRECT; 
-!define stRECT "(i, i, i, i) i"
+!define stRECT "(i, i, i, i) p"
 
 ; typedef struct tagPAINTSTRUCT { 
 ;   HDC  hdc; 
@@ -196,7 +196,7 @@
 ;   BOOL fIncUpdate; 
 ;   BYTE rgbReserved[32]; 
 ; } PAINTSTRUCT, *PPAINTSTRUCT; 
-!define stPAINTSTRUCT "(i, i, i, i, i, i, i, i, &v32) i"
+!define stPAINTSTRUCT "(p, i, i, i, i, i, i, i, &v32) p"
 
 ; typedef struct { 
 ;  UINT      cbSize; 
@@ -210,7 +210,7 @@
 ;  MSGBOXCALLBACK lpfnMsgBoxCallback; 
 ;  DWORD     dwLanguageId; 
 ; } MSGBOXPARAMS, *PMSGBOXPARAMS; 
-!define stMSGBOXPARAMS '(&l4, i, i, t, t, i, t, i, k, i) i'
+!define stMSGBOXPARAMS '(&l4, p, p, t, t, i, t, p, k, i) p'
 
 ; typedef struct _SYSTEMTIME { 
 ;    WORD wYear; 
@@ -222,7 +222,7 @@
 ;    WORD wSecond; 
 ;    WORD wMilliseconds; 
 ; } SYSTEMTIME, *PSYSTEMTIME; 
-!define stSYSTEMTIME '(&i2, &i2, &i2, &i2, &i2, &i2, &i2, &i2) i'
+!define stSYSTEMTIME '(&i2, &i2, &i2, &i2, &i2, &i2, &i2, &i2) p'
 
 ; Maximal windows path
 !define /ifndef MAX_PATH 260
@@ -239,7 +239,7 @@
 ;  TCHAR    cFileName[ MAX_PATH ]; 
 ;  TCHAR    cAlternateFileName[ 14 ]; 
 ; } WIN32_FIND_DATA, *PWIN32_FIND_DATA; 
-!define stWIN32_FIND_DATA '(i, l, l, l, i, i, i, i, &t${MAX_PATH}, &t14) i'
+!define stWIN32_FIND_DATA '(i, l, l, l, i, i, i, i, &t${MAX_PATH}, &t14) p'
 
 ; ------------- Constants --------------
 
diff --git a/Contrib/System/System.nsi b/Contrib/System/System.nsi
index ef70cdc9..cdd4c17d 100644
--- a/Contrib/System/System.nsi
+++ b/Contrib/System/System.nsi
@@ -73,7 +73,7 @@ enumex: ; End of drives or user cancel
      ; ----- Sample 3 ----- Direct proc defenition -----
 
      ; Direct specification demo
-     System::Call 'user32::MessageBox(i $HWNDPARENT, t "Just direct MessageBox specification demo ;)", t "System Example 3", i ${MB_OK}) i.s'
+     System::Call 'user32::MessageBox(p $HWNDPARENT, t "Just direct MessageBox specification demo ;)", t "System Example 3", i ${MB_OK}) i.s'
      Pop $0
 
      ; ----- Sample 4 ----- Int64, mixed definition demo -----
diff --git a/Contrib/UIs/ui.c b/Contrib/UIs/ui.c
index 2d3c8a55..aabb4d4e 100644
--- a/Contrib/UIs/ui.c
+++ b/Contrib/UIs/ui.c
@@ -18,7 +18,7 @@ const TCHAR* windows[] = {
   MAKEINTRESOURCE(IDD_UNINST)
 };
 
-BOOL CALLBACK GenericProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
+INT_PTR CALLBACK GenericProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
   static LOGBRUSH b = {BS_SOLID, RGB(255,0,0), 0};
   static HBRUSH red;
 
@@ -27,26 +27,26 @@ BOOL CALLBACK GenericProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
 
   switch (uMsg) {
     case WM_CTLCOLORSTATIC:
-      return (int)red;
+      return (INT_PTR)red;
   }
-  return 0;
+  return FALSE;
 }
 
-BOOL CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
+INT_PTR CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
   static int i = -1;
-	switch (uMsg) {
-	case WM_INITDIALOG:
-		SetWindowText(hwndDlg, _T("NSIS User Interface - Testing"));
-		SetWindowText(GetDlgItem(hwndDlg, IDC_VERSTR), _T("NSIS version"));
-		SetWindowText(GetDlgItem(hwndDlg, IDC_BACK), _T("< Back"));
-		SetWindowText(GetDlgItem(hwndDlg, IDOK), _T("Next >"));
-		SetWindowText(GetDlgItem(hwndDlg, IDCANCEL), _T("Cancel"));
-		ShowWindow(GetDlgItem(hwndDlg, IDC_BACK), SW_SHOW);
-		ShowWindow(GetDlgItem(hwndDlg, IDC_CHILDRECT), SW_SHOW);
+  switch (uMsg) {
+  case WM_INITDIALOG:
+    SetWindowText(hwndDlg, _T("NSIS User Interface - Testing"));
+    SetWindowText(GetDlgItem(hwndDlg, IDC_VERSTR), _T("NSIS version"));
+    SetWindowText(GetDlgItem(hwndDlg, IDC_BACK), _T("< Back"));
+    SetWindowText(GetDlgItem(hwndDlg, IDOK), _T("Next >"));
+    SetWindowText(GetDlgItem(hwndDlg, IDCANCEL), _T("Cancel"));
+    ShowWindow(GetDlgItem(hwndDlg, IDC_BACK), SW_SHOW);
+    ShowWindow(GetDlgItem(hwndDlg, IDC_CHILDRECT), SW_SHOW);
     SendMessage(hwndDlg, WM_COMMAND, MAKEWORD(IDOK, 0), 0);
-		ShowWindow(hwndDlg, SW_SHOW);
-		break;
-	case WM_COMMAND:
+    ShowWindow(hwndDlg, SW_SHOW);
+    break;
+  case WM_COMMAND:
     switch (LOWORD(wParam)) {
     case IDOK:
     case IDC_BACK:
@@ -77,7 +77,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg,UINT uMsg,WPARAM wParam,LPARAM lParam) {
     }
     break;
     }
-    return 0;
+    return FALSE;
 }
 
 NSIS_ENTRYPOINT_SIMPLEGUI
diff --git a/Contrib/nsDialogs/example.nsi b/Contrib/nsDialogs/example.nsi
index 242735c4..ef704089 100644
--- a/Contrib/nsDialogs/example.nsi
+++ b/Contrib/nsDialogs/example.nsi
@@ -58,7 +58,7 @@ Function OnChange
 
 	Pop $0 # HWND
 
-	System::Call user32::GetWindowText(i$EDIT,t.r0,i${NSIS_MAX_STRLEN})
+	System::Call user32::GetWindowText(p$EDIT,t.r0,i${NSIS_MAX_STRLEN})
 
 	${If} $0 == "hello there"
 		MessageBox MB_OK "right back at ya"
diff --git a/Contrib/nsDialogs/nsDialogs.c b/Contrib/nsDialogs/nsDialogs.c
index 4a5b175c..6ce7d1e8 100644
--- a/Contrib/nsDialogs/nsDialogs.c
+++ b/Contrib/nsDialogs/nsDialogs.c
@@ -32,9 +32,9 @@ struct nsControl* NSDFUNC GetControl(HWND hwCtl)
   return &g_dialog.controls[id - 1];
 }
 
-BOOL CALLBACK ParentProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK ParentProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
-  BOOL res;
+  INT_PTR res;
 
   if (message == WM_NOTIFY_OUTER_NEXT)
   {
@@ -76,7 +76,7 @@ LRESULT CALLBACK LinkWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lPar
   return CallWindowProc(ctl->oldWndProc, hwnd, message, wParam, lParam);
 }
 
-BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   switch (uMsg)
   {
@@ -93,7 +93,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       {
         if (ctl->callbacks.onClick)
         {
-          pushint((int) hwCtl);
+          pushintptr((INT_PTR) hwCtl);
           g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onClick - 1, 0);
         }
       }
@@ -101,7 +101,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       {
         if (ctl->callbacks.onChange)
         {
-          pushint((int) hwCtl);
+          pushintptr((INT_PTR) hwCtl);
           g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onChange - 1, 0);
         }
       }
@@ -109,7 +109,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       {
         if (ctl->callbacks.onChange)
         {
-          pushint((int) hwCtl);
+          pushintptr((INT_PTR) hwCtl);
           g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onChange - 1, 0);
         }
       }
@@ -118,7 +118,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       {
         if (ctl->callbacks.onChange)
         {
-          pushint((int) hwCtl);
+          pushintptr((INT_PTR) hwCtl);
           g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onChange - 1, 0);
         }
       }
@@ -126,7 +126,7 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       {
         if (ctl->callbacks.onClick)
         {
-          pushint((int) hwCtl);
+          pushintptr((INT_PTR) hwCtl);
           g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onClick - 1, 0);
         }
       }
@@ -145,9 +145,9 @@ BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       if (!ctl->callbacks.onNotify)
         break;
 
-      pushint((int) nmhdr);
-      pushint(nmhdr->code);
-      pushint((int) nmhdr->hwndFrom);
+      pushintptr((INT_PTR) nmhdr);
+      pushintptr(nmhdr->code);
+      pushintptr((INT_PTR) nmhdr->hwndFrom);
       g_pluginParms->ExecuteCodeSegment(ctl->callbacks.onNotify - 1, 0);
     }
 
@@ -287,7 +287,7 @@ void __declspec(dllexport) Create(HWND hwndParent, int string_size, TCHAR *varia
 
   g_dialog.callbacks.onBack = 0;
 
-  pushint((int) g_dialog.hwDialog);
+  pushintptr((INT_PTR) g_dialog.hwDialog);
 }
 
 void __declspec(dllexport) CreateControl(HWND hwndParent, int string_size, TCHAR *variables, stack_t **stacktop, extra_parameters *extra)
@@ -393,7 +393,7 @@ void __declspec(dllexport) CreateControl(HWND hwndParent, int string_size, TCHAR
 
   // push back result
 
-  pushint((int) hwItem);
+  pushintptr((INT_PTR) hwItem);
 
   // done
 
@@ -413,11 +413,11 @@ void __declspec(dllexport) SetUserData(HWND hwndParent, int string_size, TCHAR *
 
   // get info from stack
 
-  hwCtl = (HWND) popint();
+  hwCtl = (HWND) popintptr();
 
   if (!IsWindow(hwCtl))
   {
-    popint(); // remove user data from stack
+    popintptr(); // remove user data from stack
     return;
   }
 
@@ -440,7 +440,7 @@ void __declspec(dllexport) GetUserData(HWND hwndParent, int string_size, TCHAR *
 
   // get info from stack
 
-  hwCtl = (HWND) popint();
+  hwCtl = (HWND) popintptr();
 
   if (!IsWindow(hwCtl))
   {
@@ -513,7 +513,7 @@ void NSDFUNC SetControlCallback(size_t callbackIdx)
 
   // get info from stack
 
-  hwCtl = (HWND) popint();
+  hwCtl = (HWND) popintptr();
   callback = (nsFunction) popint();
 
   if (!IsWindow(hwCtl))
diff --git a/Contrib/nsDialogs/nsDialogs.nsh b/Contrib/nsDialogs/nsDialogs.nsh
index 68c64875..ac528574 100644
--- a/Contrib/nsDialogs/nsDialogs.nsh
+++ b/Contrib/nsDialogs/nsDialogs.nsh
@@ -354,9 +354,9 @@ Header file for creating custom installer pages with nsDialogs
 
 !macro _NSD_GWLAddFlags GWL HWND DATA
 
-	System::Call "user32::GetWindowLong(i${HWND},i${GWL})i.s"
+	System::Call "user32::GetWindowLong(p${HWND},i${GWL})p.s"
 	System::Int64Op "${DATA}" |
-	System::Call "user32::SetWindowLong(i${HWND},i${GWL},is)"
+	System::Call "user32::SetWindowLong(p${HWND},p${GWL},ps)"
 
 !macroend
 
@@ -365,7 +365,7 @@ Header file for creating custom installer pages with nsDialogs
 
 !macro __NSD_GetText CONTROL VAR
 
-	System::Call user32::GetWindowText(i${CONTROL},t.s,i${NSIS_MAX_STRLEN})
+	System::Call user32::GetWindowText(p${CONTROL},t.s,i${NSIS_MAX_STRLEN})
 	Pop ${VAR}
 
 !macroend
@@ -422,7 +422,7 @@ Header file for creating custom installer pages with nsDialogs
 
 !macro __NSD_SetFocus HWND
 
-	System::Call "user32::SetFocus(i${HWND})"
+	System::Call "user32::SetFocus(p${HWND})"
   
 !macroend
 
@@ -492,7 +492,7 @@ Header file for creating custom installer pages with nsDialogs
 !macro __NSD_LB_GetSelection CONTROL VAR
 
 	SendMessage ${CONTROL} ${LB_GETCURSEL} 0 0 ${VAR}
-	System::Call 'user32::SendMessage(i ${CONTROL}, i ${LB_GETTEXT}, i ${VAR}, t .s)'
+	System::Call 'user32::SendMessage(p ${CONTROL}, i ${LB_GETTEXT}, p ${VAR}, t .s)'
 	Pop ${VAR}
 
 !macroend
@@ -511,10 +511,10 @@ Header file for creating custom installer pages with nsDialogs
 	!if "${_LIHINSTMODE}" == "exeresource"
 		!undef _LIHINSTSRC     # If (internal?) _* macro params starts using $0, 
 		!define _LIHINSTSRC r0 # _LIHINSTSRC can be changed to s
-		System::Call 'kernel32::GetModuleHandle(i0)i.${_LIHINSTSRC}' 
+		System::Call 'kernel32::GetModuleHandle(p0)p.${_LIHINSTSRC}' 
 	!endif
 	
-	System::Call 'user32::LoadImage(i ${_LIHINSTSRC}, ts, i ${_IMGTYPE}, i0, i0, i${_LIFLAGS}) i.r0'
+	System::Call 'user32::LoadImage(p ${_LIHINSTSRC}, ts, i ${_IMGTYPE}, i0, i0, i${_LIFLAGS})p.r0'
 	SendMessage $R0 ${STM_SETIMAGE} ${_IMGTYPE} $0
 
 	Pop $R0
@@ -549,25 +549,19 @@ Header file for creating custom installer pages with nsDialogs
 
 	StrCpy $R0 ${CONTROL} # in case ${CONTROL} is $0
 
-	StrCpy $1 ""
-	StrCpy $2 ""
-
-	System::Call '*(i, i, i, i) i.s'
-	Pop $0
-
+	# Allocate a RECT in $0 and initialize $1 and $2 to 0
+	System::Call '*(i0r1, i0r2, i, i)p.r0'
 	${If} $0 <> 0
-	
-		System::Call 'user32::GetClientRect(iR0, ir0)'
+		System::Call 'user32::GetClientRect(pR0, pr0)'
 		System::Call '*$0(i, i, i .s, i .s)'
 		System::Free $0
 		Pop $1
 		Pop $2
-
 	${EndIf}
 
-	System::Call 'user32::LoadImage(i0, ts, i ${IMAGE_BITMAP}, ir1, ir2, i${LR_LOADFROMFILE}) i.s' "${IMAGE}"
+	System::Call 'user32::LoadImage(p0, ts, i ${IMAGE_BITMAP}, ir1, ir2, i${LR_LOADFROMFILE}) p.s' "${IMAGE}"
 	Pop $0
-    SendMessage $R0 ${STM_SETIMAGE} ${IMAGE_BITMAP} $0
+	SendMessage $R0 ${STM_SETIMAGE} ${IMAGE_BITMAP} $0
 
 	Pop $R0
 	Pop $2
@@ -583,9 +577,7 @@ Header file for creating custom installer pages with nsDialogs
 !macro __NSD_FreeImage IMAGE
 
 	${If} ${IMAGE} <> 0
-
-		System::Call gdi32::DeleteObject(is) ${IMAGE}
-
+		System::Call gdi32::DeleteObject(ps) ${IMAGE}
 	${EndIf}
 
 !macroend
@@ -594,7 +586,7 @@ Header file for creating custom installer pages with nsDialogs
 !define NSD_FreeBitmap `${NSD_FreeImage}`
 
 !macro __NSD_FreeIcon IMAGE
-	System::Call user32::DestroyIcon(is) ${IMAGE}
+	System::Call user32::DestroyIcon(ps) ${IMAGE}
 !macroend
 
 !define NSD_FreeIcon `!insertmacro __NSD_FreeIcon`
diff --git a/Contrib/nsDialogs/welcome.nsi b/Contrib/nsDialogs/welcome.nsi
index 29a90e71..cee2ec89 100644
--- a/Contrib/nsDialogs/welcome.nsi
+++ b/Contrib/nsDialogs/welcome.nsi
@@ -96,7 +96,7 @@ Function nsDialogsWelcome
 	Pop $IMAGECTL
 
 	StrCpy $0 $PLUGINSDIR\welcome.bmp
-	System::Call 'user32::LoadImage(i 0, t r0, i ${IMAGE_BITMAP}, i 0, i 0, i ${LR_LOADFROMFILE}) i.s'
+	System::Call 'user32::LoadImage(p 0, t r0, i ${IMAGE_BITMAP}, i 0, i 0, i ${LR_LOADFROMFILE})p.s'
 	Pop $IMAGE
 	
 	SendMessage $IMAGECTL ${STM_SETIMAGE} ${IMAGE_BITMAP} $IMAGE
@@ -119,7 +119,7 @@ Function nsDialogsWelcome
 
 	Call ShowControls
 
-	System::Call gdi32::DeleteObject(i$IMAGE)
+	System::Call gdi32::DeleteObject(p$IMAGE)
 
 FunctionEnd
 
@@ -198,7 +198,7 @@ Function DirChange
 
 	GetDlgItem $0 $HWNDPARENT 1
 
-	System::Call user32::GetWindowText(i$DIRECTORY,t.d,i${NSIS_MAX_STRLEN})
+	System::Call user32::GetWindowText(p$DIRECTORY,t.d,i${NSIS_MAX_STRLEN})
 
 	${If} ${FileExists} $INSTDIR\makensis.exe
 		EnableWindow $0 1
diff --git a/Contrib/zip2exe/main.cpp b/Contrib/zip2exe/main.cpp
index 4f64a17d..c2e6c39c 100644
--- a/Contrib/zip2exe/main.cpp
+++ b/Contrib/zip2exe/main.cpp
@@ -76,7 +76,7 @@ int g_zipfile_size;
 bool g_made;
 
 
-static BOOL CALLBACK DlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK DlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 NSIS_ENTRYPOINT_SIMPLEGUI
 int WINAPI _tWinMain(HINSTANCE hInst,HINSTANCE hOldInst,LPTSTR CmdLineParams,int ShowCmd)
@@ -600,7 +600,7 @@ void SetZip(HWND hwndDlg, TCHAR *path)
   }
 }
 
-BOOL CALLBACK DlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK DlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   static int ids[]={IDC_INFO,IDC_NSISICON,IDC_SZIPFRAME,IDC_BROWSE,IDC_ZIPFILE,IDC_ZIPINFO_SUMMARY,IDC_ZIPINFO_FILES,IDC_OFRAME,IDC_INAMEST,
                         IDC_INSTNAME,IDC_INSTPATH,IDC_OEFST,IDC_OUTFILE,IDC_BROWSE2,IDC_COMPRESSOR,IDC_ZLIB,IDC_BZIP2,IDC_LZMA,IDC_SOLID,IDC_INTERFACE,IDC_MODERNUI,IDC_CLASSICUI,IDC_UNICODE};
@@ -783,5 +783,5 @@ BOOL CALLBACK DlgProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
       }
     break;
   }
-  return 0;
+  return FALSE;
 }
diff --git a/Docs/src/usefulfunc.but b/Docs/src/usefulfunc.but
index 9e653780..1b8d0836 100644
--- a/Docs/src/usefulfunc.but
+++ b/Docs/src/usefulfunc.but
@@ -141,14 +141,14 @@
 
 \H{installerfilename} Get Installer Filename
 
-\c  System::Call 'kernel32::GetModuleFileNameA(i 0, t .R0, i 1024) i r1'
+\c  System::Call 'kernel32::GetModuleFileName(p 0, t .R0, i 1024) i r1'
 \c  ;$R0 will contain the installer filename
 
 \H{multipleinstances} Prevent Multiple Instances
 
 Put the following code in your \R{oninit}{.onInit function}:
 
-\c  System::Call 'kernel32::CreateMutexA(i 0, i 0, t "myMutex") i .r1 ?e'
+\c  System::Call 'kernel32::CreateMutex(p 0, i 0, t "myMutex") p .r1 ?e'
 \c  Pop $R0
 \c  
 \c  StrCmp $R0 0 +3
diff --git a/Docs/src/usefulinfos.but b/Docs/src/usefulinfos.but
index 9f23dae9..5bf04d4d 100644
--- a/Docs/src/usefulinfos.but
+++ b/Docs/src/usefulinfos.but
@@ -234,10 +234,10 @@ Here is the function:
 \c     System::StrAlloc ${NSIS_MAX_STRLEN}
 \c     Pop $3
 \c     StrCpy $2 0
-\c     System::Call "*(i, i, i, i, i, i, i, i, i) i \
+\c     System::Call "*(i, i, i, i, i, i, i, i, i) p \
 \c       (0, 0, 0, 0, 0, r3, ${NSIS_MAX_STRLEN}) .r1"
 \c     loop: StrCmp $2 $6 done
-\c       System::Call "User32::SendMessage(i, i, i, i) i \
+\c       System::Call "User32::SendMessage(p, i, p, p) i \
 \c         ($0, ${LVM_GETITEMTEXT}, $2, r1)"
 \c       System::Call "*$3(&t${NSIS_MAX_STRLEN} .r4)"
 \c       FileWrite $5 "$4$\r$\n"
@@ -286,10 +286,10 @@ Here's the function to generate a Unicode file if you're building a \R{intro-uni
 \c     System::StrAlloc ${NSIS_MAX_STRLEN}
 \c     Pop $3
 \c     StrCpy $2 0
-\c     System::Call "*(i, i, i, i, i, i, i, i, i) i \
+\c     System::Call "*(i, i, i, i, i, i, i, i, i) p \
 \c       (0, 0, 0, 0, 0, r3, ${NSIS_MAX_STRLEN}) .r1"
 \c     loop: StrCmp $2 $6 done
-\c       System::Call "User32::SendMessageW(i, i, i, i) i \
+\c       System::Call "User32::SendMessageW(p, i, p, p) i \
 \c         ($0, ${LVM_GETITEMTEXT}, $2, r1)"
 \c       System::Call "*$3(&t${NSIS_MAX_STRLEN} .r4)"
 \c       FileWriteUTF16LE $5 "$4$\r$\n"
diff --git a/Examples/makensis.nsi b/Examples/makensis.nsi
index 10300a50..d07c03ca 100644
--- a/Examples/makensis.nsi
+++ b/Examples/makensis.nsi
@@ -11,12 +11,20 @@
 ;--------------------------------
 ;Configuration
 
-!ifdef OUTFILE
-  OutFile "${OUTFILE}"
+!ifdef NSIS_MAKENSIS64
+  !define BITS 64
+  !define NAMESUFFIX " (64 bit)"
 !else
-  OutFile ..\nsis-${VERSION}-setup.exe
+  !define BITS 32
+  !define NAMESUFFIX ""
 !endif
 
+!ifndef OUTFILE
+  !define OUTFILE "..\nsis${BITS}-${VERSION}-setup.exe"
+  !searchreplace OUTFILE "${OUTFILE}" nsis32 nsis
+!endif
+
+OutFile "${OUTFILE}"
 Unicode true
 SetCompressor /SOLID lzma
 
@@ -24,7 +32,7 @@ InstType "Full"
 InstType "Lite"
 InstType "Minimal"
 
-InstallDir $PROGRAMFILES\NSIS
+InstallDir $PROGRAMFILES${BITS}\NSIS
 InstallDirRegKey HKLM Software\NSIS ""
 
 RequestExecutionLevel admin
@@ -49,7 +57,7 @@ RequestExecutionLevel admin
 
 ;Names
 Name "NSIS"
-Caption "NSIS ${VERSION} Setup"
+Caption "NSIS ${VERSION}${NAMESUFFIX} Setup"
 
 !define REG_UNINST_KEY "Software\Microsoft\Windows\CurrentVersion\Uninstall\NSIS"
 
@@ -114,11 +122,17 @@ VIAddVersionKey "LegalCopyright" "http://nsis.sf.net/License"
 !macro InstallPlugin pi
   File "/oname=$InstDir\Plugins\x86-ansi\${pi}.dll" ..\Plugins\x86-ansi\${pi}.dll
   File "/oname=$InstDir\Plugins\x86-unicode\${pi}.dll" ..\Plugins\x86-unicode\${pi}.dll
+  !ifdef NSIS_MAKENSIS64
+    File "/oname=$InstDir\Plugins\amd64-unicode\${pi}.dll" ..\Plugins\amd64-unicode\${pi}.dll
+  !endif
 !macroend
 
 !macro InstallStub stub
   File ..\Stubs\${stub}-x86-ansi
   File ..\Stubs\${stub}-x86-unicode
+  !ifdef NSIS_MAKENSIS64
+    File ..\Stubs\${stub}-amd64-unicode
+  !endif
 !macroend
 
 ${MementoSection} "NSIS Core Files (required)" SecCore
@@ -218,6 +232,9 @@ ${MementoSection} "NSIS Core Files (required)" SecCore
 
   CreateDirectory $INSTDIR\Plugins\x86-ansi
   CreateDirectory $INSTDIR\Plugins\x86-unicode
+  !ifdef NSIS_MAKENSIS64
+    CreateDirectory $INSTDIR\Plugins\amd64-unicode
+  !endif
   !insertmacro InstallPlugin TypeLib
 
   ReadRegStr $R0 HKCR ".nsi" ""
@@ -330,10 +347,10 @@ ${MementoSection} "Desktop Shortcut" SecShortcuts
   SectionIn 1 2
   SetOutPath $INSTDIR
 !ifndef NO_STARTMENUSHORTCUTS
-  CreateShortCut "$SMPROGRAMS\NSIS.lnk" "$INSTDIR\NSIS.exe"
+  CreateShortCut "$SMPROGRAMS\NSIS${NAMESUFFIX}.lnk" "$INSTDIR\NSIS.exe"
 !endif
 
-  CreateShortCut "$DESKTOP\NSIS.lnk" "$INSTDIR\NSIS.exe"
+  CreateShortCut "$DESKTOP\NSIS${NAMESUFFIX}.lnk" "$INSTDIR\NSIS.exe"
 
 ${MementoSectionEnd}
 
@@ -797,7 +814,7 @@ Section -post
 
   WriteRegExpandStr HKLM "${REG_UNINST_KEY}" "UninstallString" '"$INSTDIR\uninst-nsis.exe"'
   WriteRegExpandStr HKLM "${REG_UNINST_KEY}" "InstallLocation" "$INSTDIR"
-  WriteRegStr HKLM "${REG_UNINST_KEY}" "DisplayName" "Nullsoft Install System"
+  WriteRegStr HKLM "${REG_UNINST_KEY}" "DisplayName" "Nullsoft Install System${NAMESUFFIX}"
   WriteRegStr HKLM "${REG_UNINST_KEY}" "DisplayIcon" "$INSTDIR\NSIS.exe,0"
   WriteRegStr HKLM "${REG_UNINST_KEY}" "DisplayVersion" "${VERSION}"
 !ifdef VER_MAJOR & VER_MINOR & VER_REVISION & VER_BUILD
@@ -1032,8 +1049,8 @@ Section Uninstall
   DetailPrint "Deleting Files..."
   SetDetailsPrint listonly
 
-  Delete $SMPROGRAMS\NSIS.lnk
-  Delete $DESKTOP\NSIS.lnk
+  Delete "$SMPROGRAMS\NSIS${NAMESUFFIX}.lnk"
+  Delete "$DESKTOP\NSIS${NAMESUFFIX}.lnk"
   Delete $INSTDIR\makensis.exe
   Delete $INSTDIR\makensisw.exe
   Delete $INSTDIR\NSIS.exe
diff --git a/Include/FileFunc.nsh b/Include/FileFunc.nsh
index a6ba591b..76f4cbe8 100644
--- a/Include/FileFunc.nsh
+++ b/Include/FileFunc.nsh
@@ -1107,22 +1107,22 @@ RefreshShellIcons
 
 	FileFunc_GetTime_getfile:
 	IfFileExists $0 0 FileFunc_GetTime_error
-	System::Call '*(i,l,l,l,i,i,i,i,&t260,&t14) i .r6'
-	System::Call 'kernel32::FindFirstFile(t,i)i(r0,r6) .r2'
+	System::Call '*(i,l,l,l,i,i,i,i,&t260,&t14) p .r6'
+	System::Call 'kernel32::FindFirstFile(t,p)p(r0,r6) .r2'
 	System::Call 'kernel32::FindClose(i)i(r2)'
 
 	FileFunc_GetTime_gettime:
-	System::Call '*(&i2,&i2,&i2,&i2,&i2,&i2,&i2,&i2) i .r7'
+	System::Call '*(&i2,&i2,&i2,&i2,&i2,&i2,&i2,&i2) p .r7'
 	StrCmp $1 'L' 0 FileFunc_GetTime_systemtime
-	System::Call 'kernel32::GetLocalTime(i)i(r7)'
+	System::Call 'kernel32::GetLocalTime(p)i(r7)'
 	goto FileFunc_GetTime_convert
 	FileFunc_GetTime_systemtime:
 	StrCmp $1 'LS' 0 FileFunc_GetTime_filetime
-	System::Call 'kernel32::GetSystemTime(i)i(r7)'
+	System::Call 'kernel32::GetSystemTime(p)i(r7)'
 	goto FileFunc_GetTime_convert
 
 	FileFunc_GetTime_filetime:
-	System::Call '*$6(i,l,l,l,i,i,i,i,&t260,&t14)i(,.r4,.r3,.r2)'
+	System::Call '*$6(i,l,l,l,i,i,i,i,&t260,&t14)p(,.r4,.r3,.r2)'
 	System::Free $6
 	StrCmp $1 'A' 0 +3
 	StrCpy $2 $3
@@ -1146,7 +1146,7 @@ RefreshShellIcons
 	System::Call 'kernel32::FileTimeToSystemTime(*l,i)i(r3,r7)'
 
 	FileFunc_GetTime_convert:
-	System::Call '*$7(&i2,&i2,&i2,&i2,&i2,&i2,&i2,&i2)i(.r5,.r6,.r4,.r0,.r3,.r2,.r1,)'
+	System::Call '*$7(&i2,&i2,&i2,&i2,&i2,&i2,&i2,&i2)p(.r5,.r6,.r4,.r0,.r3,.r2,.r1,)'
 	System::Free $7
 
 	IntCmp $0 9 0 0 +2
@@ -1398,7 +1398,7 @@ RefreshShellIcons
 	Push $0
 	Push $1
 	Push $2
-	System::Call 'kernel32::GetModuleFileName(i 0, t .r0, i 1024)'
+	System::Call 'kernel32::GetModuleFileName(p 0, t .r0, i 1024)'
 	System::Call 'kernel32::GetLongPathName(t r0, t .r1, i 1024)i .r2'
 	StrCmp $2 error +2
 	StrCpy $0 $1
diff --git a/Include/StrFunc.nsh b/Include/StrFunc.nsh
index 64f91c11..e8c9b70e 100644
--- a/Include/StrFunc.nsh
+++ b/Include/StrFunc.nsh
@@ -285,7 +285,7 @@ o-----------------------------------------------------------------------------o
           ; Else convert to lower case.
 
           ;Use "IsCharAlpha" for the job
-          System::Call "*(&t1 r7) i .r8"
+          System::Call "*(&t1 r7) p .r8"
           System::Call "*$8(&i1 .r7)"
           System::Free $8
           System::Call "user32::IsCharAlpha(i r7) i .r8"
@@ -325,7 +325,7 @@ o-----------------------------------------------------------------------------o
           ; Switch all characters cases to their inverse case.
 
           ;Use "IsCharUpper" for the job
-          System::Call "*(&t1 r6) i .r8"
+          System::Call "*(&t1 r6) p .r8"
           System::Call "*$8(&i1 .r7)"
           System::Free $8
           System::Call "user32::IsCharUpper(i r7) i .r8"
@@ -395,7 +395,7 @@ o-----------------------------------------------------------------------------o
       StrCpy $4 ""
 
       ;Open the clipboard to do the operations the user chose (kichik's fix)
-      System::Call 'user32::OpenClipboard(i $HWNDPARENT)'
+      System::Call 'user32::OpenClipboard(p $HWNDPARENT)'
 
       ${If} $1 == ">" ;Set
 
@@ -405,44 +405,44 @@ o-----------------------------------------------------------------------------o
         ;Step 2: Allocate global heap
         StrLen $2 $0
         IntOp $2 $2 + 1
-		IntOp $2 $2 * ${NSIS_CHAR_SIZE}
-        System::Call 'kernel32::GlobalAlloc(i 2, i r2) i.r2'
+        IntOp $2 $2 * ${NSIS_CHAR_SIZE}
+        System::Call 'kernel32::GlobalAlloc(i 2, i r2) p.r2'
 
         ;Step 3: Lock the handle
-        System::Call 'kernel32::GlobalLock(i r2) i.r3'
+        System::Call 'kernel32::GlobalLock(p r2) i.r3'
 
         ;Step 4: Copy the text to locked clipboard buffer
-        System::Call 'kernel32::lstrcpy(i r3, t r0)'
+        System::Call 'kernel32::lstrcpy(p r3, t r0)'
 
         ;Step 5: Unlock the handle again
-        System::Call 'kernel32::GlobalUnlock(i r2)'
+        System::Call 'kernel32::GlobalUnlock(p r2)'
 
         ;Step 6: Set the information to the clipboard
-        System::Call 'user32::SetClipboardData(i 1, i r2)'
+        System::Call 'user32::SetClipboardData(i 1, p r2)'
 
         StrCpy $0 ""
 
       ${ElseIf} $1 == "<" ;Get
 
         ;Step 1: Get clipboard data
-        System::Call 'user32::GetClipboardData(i 1) i .r2'
+        System::Call 'user32::GetClipboardData(i 1) p .r2'
 
         ;Step 2: Lock and copy data (kichik's fix)
-        System::Call 'kernel32::GlobalLock(i r2) t .r0'
+        System::Call 'kernel32::GlobalLock(p r2) t .r0'
 
         ;Step 3: Unlock (kichik's fix)
-        System::Call 'kernel32::GlobalUnlock(i r2)'
+        System::Call 'kernel32::GlobalUnlock(p r2)'
 
       ${ElseIf} $1 == "<>" ;Swap
 
         ;Step 1: Get clipboard data
-        System::Call 'user32::GetClipboardData(i 1) i .r2'
+        System::Call 'user32::GetClipboardData(i 1) p .r2'
 
         ;Step 2: Lock and copy data (kichik's fix)
-        System::Call 'kernel32::GlobalLock(i r2) t .r4'
+        System::Call 'kernel32::GlobalLock(p r2) t .r4'
 
         ;Step 3: Unlock (kichik's fix)
-        System::Call 'kernel32::GlobalUnlock(i r2)'
+        System::Call 'kernel32::GlobalUnlock(p r2)'
 
         ;Step 4: Clear the clipboard
         System::Call 'user32::EmptyClipboard()'
@@ -451,19 +451,19 @@ o-----------------------------------------------------------------------------o
         StrLen $2 $0
         IntOp $2 $2 + 1
 		IntOp $2 $2 * ${NSIS_CHAR_SIZE}
-        System::Call 'kernel32::GlobalAlloc(i 2, i r2) i.r2'
+        System::Call 'kernel32::GlobalAlloc(i 2, i r2) p.r2'
 
         ;Step 6: Lock the handle
-        System::Call 'kernel32::GlobalLock(i r2) i.r3'
+        System::Call 'kernel32::GlobalLock(p r2) i.r3'
 
         ;Step 7: Copy the text to locked clipboard buffer
-        System::Call 'kernel32::lstrcpy(i r3, t r0)'
+        System::Call 'kernel32::lstrcpy(p r3, t r0)'
 
         ;Step 8: Unlock the handle again
-        System::Call 'kernel32::GlobalUnlock(i r2)'
+        System::Call 'kernel32::GlobalUnlock(p r2)'
 
         ;Step 9: Set the information to the clipboard
-        System::Call 'user32::SetClipboardData(i 1, i r2)'
+        System::Call 'user32::SetClipboardData(i 1, p r2)'
         
         StrCpy $0 $4
       ${Else} ;Clear
diff --git a/Include/TextFunc.nsh b/Include/TextFunc.nsh
index 67678207..230835b6 100644
--- a/Include/TextFunc.nsh
+++ b/Include/TextFunc.nsh
@@ -1043,12 +1043,12 @@ TrimNewLines
 	System::Alloc $6
 	Pop $0
 	FileSeek $3 $5 SET
-	System::Call 'kernel32::ReadFile(i r3, i r0, i $6, t.,)'
+	System::Call 'kernel32::ReadFile(p r3, p r0, i $6, t.,)'
 	FileSeek $3 $4 SET
 	StrCmp${_TEXTFUNC_S} $2 '' +2
 	FileWrite $3 '$1$2$\r$\n'
-	System::Call 'kernel32::WriteFile(i r3, i r0, i $6, t.,)'
-	System::Call 'kernel32::SetEndOfFile(i r3)'
+	System::Call 'kernel32::WriteFile(p r3, p r0, i $6, t.,)'
+	System::Call 'kernel32::SetEndOfFile(p r3)'
 	System::Free $0
 	StrCmp${_TEXTFUNC_S} $2 '' +3
 	StrCpy $0 CHANGED
@@ -1153,10 +1153,10 @@ TrimNewLines
 	System::Alloc $3
 	Pop $4
 	FileSeek $2 0 SET
-	System::Call 'kernel32::ReadFile(i r2, i r4, i $3, t.,)'
-	System::Call 'user32::$1Buff(i r4, i r4, i $3)'
+	System::Call 'kernel32::ReadFile(p r2, p r4, i $3, t.,)'
+	System::Call 'user32::$1Buff(p r4, p r4, i $3)'
 	FileSeek $2 0 SET
-	System::Call 'kernel32::WriteFile(i r2, i r4, i $3, t.,)'
+	System::Call 'kernel32::WriteFile(p r2, p r4, i $3, t.,)'
 	System::Free $4
 	FileClose $2
 	goto TextFunc_FileRecode_end
diff --git a/Include/x64.nsh b/Include/x64.nsh
index e694c1e6..a35e0990 100644
--- a/Include/x64.nsh
+++ b/Include/x64.nsh
@@ -27,8 +27,8 @@
 
 !macro _RunningX64 _a _b _t _f
   !insertmacro _LOGICLIB_TEMP
-  System::Call kernel32::GetCurrentProcess()i.s
-  System::Call kernel32::IsWow64Process(is,*i.s)
+  System::Call kernel32::GetCurrentProcess()p.s
+  System::Call kernel32::IsWow64Process(ps,*i.s)
   Pop $_LOGICLIB_TEMP
   !insertmacro _!= $_LOGICLIB_TEMP 0 `${_t}` `${_f}`
 !macroend
diff --git a/SConstruct b/SConstruct
index e6203579..b4b047d5 100644
--- a/SConstruct
+++ b/SConstruct
@@ -66,16 +66,17 @@ doctypes = [
 
 path = ARGUMENTS.get('PATH', '')
 toolset = ARGUMENTS.get('TOOLSET', '')
+arch = ARGUMENTS.get('TARGET_ARCH', 'x86')
 
 if toolset and path:
-	defenv = Environment(TARGET_ARCH = 'x86', ENV = {'PATH' : path}, TOOLS = toolset.split(',') + ['zip'])
+	defenv = Environment(TARGET_ARCH = arch, ENV = {'PATH' : path}, TOOLS = toolset.split(',') + ['zip'])
 else:
 	if path:
-		defenv = Environment(TARGET_ARCH = 'x86', ENV = {'PATH' : path})
+		defenv = Environment(TARGET_ARCH = arch, ENV = {'PATH' : path})
 	if toolset:
-		defenv = Environment(TARGET_ARCH = 'x86', TOOLS = toolset.split(',') + ['zip'])
+		defenv = Environment(TARGET_ARCH = arch, TOOLS = toolset.split(',') + ['zip'])
 if not toolset and not path:
-	defenv = Environment(TARGET_ARCH = 'x86')
+	defenv = Environment(TARGET_ARCH = arch)
 
 Export('defenv')
 
@@ -170,6 +171,7 @@ opts.Add(('PATH', 'A colon-separated list of system paths instead of the default
 opts.Add(('TOOLSET', 'A comma-separated list of specific tools used for building instead of the default', None))
 opts.Add(BoolVariable('MSTOOLKIT', 'Use Microsoft Visual C++ Toolkit', 'no'))
 opts.Add(EnumVariable('MSVS_VERSION', 'MS Visual C++ version', os.environ.get('MSVS_VERSION'), allowed_values=('6.0', '7.0', '7.1', '8.0', '8.0Exp', '9.0', '9.0Exp', '10.0', '10.0Exp')))
+opts.Add(EnumVariable('TARGET_ARCH', 'Target processor architecture', 'x86', allowed_values=('x86', 'amd64')))
 opts.Add(ListVariable('DOCTYPES', 'A list of document types that will be built', default_doctype, doctypes))
 opts.Add(PathVariable('APPEND_CPPPATH', 'Additional paths to search for include files', None))
 opts.Add(PathVariable('APPEND_LIBPATH', 'Additional paths to search for libraries', None))
@@ -196,6 +198,9 @@ opts.Add(('PREFIX_PLUGINAPI_LIB','Path to install plugin static library to.', No
 opts.Update(defenv)
 Help(opts.GenerateHelpText(defenv))
 
+if defenv['TARGET_ARCH'] != 'x86':
+	defenv['UNICODE'] = True
+
 # add prefixes defines
 if 'NSIS_CONFIG_CONST_DATA_PATH' in defenv['NSIS_CPPDEFINES']:
 	defenv.Append(NSIS_CPPDEFINES = [('PREFIX_CONF', '"%s"' % defenv.subst('$PREFIX_CONF'))])
@@ -324,6 +329,8 @@ defenv['INSTDISTDIR'] = defenv.Dir('#.instdist')
 defenv['TESTDISTDIR'] = defenv.Dir('#.test')
 defenv['DISTSUFFIX'] = ''
 
+if defenv['TARGET_ARCH'] == 'amd64':
+	defenv['DISTSUFFIX'] += '-amd64'
 if defenv.has_key('CODESIGNER'):
 	defenv['DISTSUFFIX'] = '-signed'
 
@@ -609,6 +616,7 @@ for stub in stubs:
 	if GetArcCPU(defenv)=='x86':
 		BuildStub(stub, False, False)
 		BuildStub(stub, True, False)
+	# BUGBUG64: Should build x86 stubs on x64?
 
 defenv.DistributeStubs('Source/exehead/uninst.ico',names='uninst')
 
diff --git a/Source/Tests/winver.nsi b/Source/Tests/winver.nsi
index a5b21e50..8e60bb9c 100644
--- a/Source/Tests/winver.nsi
+++ b/Source/Tests/winver.nsi
@@ -20,7 +20,7 @@
 #        System::Alloc 156
 #        Pop $0
 #        System::Call *$0(ir1)
-#        System::Call kernel32::GetVersionEx(ir0)i.R0
+#        System::Call kernel32::GetVersionEx(pr0)i.R0
 #
 #        DetailPrint 'StrCpy $2_RES $R0'
 #
diff --git a/Source/build.cpp b/Source/build.cpp
index ff19264a..b976b434 100644
--- a/Source/build.cpp
+++ b/Source/build.cpp
@@ -149,6 +149,7 @@ CEXEBuild::CEXEBuild() :
 #ifdef _UNICODE
   definedlist.add(_T("NSIS_UNICODE_MAKENSIS")); // This define might go away once makensis.exe is always unicode
 #endif
+  if (sizeof(void*) > 4) definedlist.add(_T("NSIS_MAKENSIS64"));
 
   db_opt_save=db_comp_save=db_full_size=db_opt_save_u=db_comp_save_u=db_full_size_u=0;
 
@@ -3645,6 +3646,7 @@ void CEXEBuild::set_target_architecture_predefines()
 {
   definedlist.del(_T("NSIS_UNICODE"));
   definedlist.del(_T("NSIS_CHAR_SIZE"));
+  definedlist.del(_T("NSIS_PTR_SIZE"));
   if (build_unicode)
   {
     definedlist.add(_T("NSIS_UNICODE"));
@@ -3654,6 +3656,7 @@ void CEXEBuild::set_target_architecture_predefines()
   {
     definedlist.add(_T("NSIS_CHAR_SIZE"), _T("1"));
   }
+  definedlist.add(_T("NSIS_PTR_SIZE"), m_target_type <= TARGET_X86UNICODE ? _T("4") : _T("8"));
 }
 
 int CEXEBuild::change_target_architecture()
@@ -3664,7 +3667,7 @@ int CEXEBuild::change_target_architecture()
     return PS_ERROR;
   }
 
-  m_target_type = build_unicode ? TARGET_X86UNICODE : TARGET_X86ANSI;
+  m_target_type = build_unicode ? TARGET_X86UNICODE : TARGET_X86ANSI; // BUGBUG64
   set_target_architecture_predefines();
 
   int ec = load_stub();
@@ -3708,6 +3711,9 @@ const TCHAR* CEXEBuild::get_target_suffix(CEXEBuild::TARGETTYPE tt) const
   {
   case TARGET_X86ANSI   :return _T("x86-ansi");
   case TARGET_X86UNICODE:return _T("x86-unicode");
+#if !defined(_WIN32) || defined(_WIN64)
+  case TARGET_AMD64     :return _T("amd64-unicode");
+#endif
   default:return _T("?");
   }
 }
diff --git a/Source/build.h b/Source/build.h
index 81499774..8e169f6c 100644
--- a/Source/build.h
+++ b/Source/build.h
@@ -120,6 +120,7 @@ class CEXEBuild {
       TARGETFIRST,
       TARGET_X86ANSI = TARGETFIRST,
       TARGET_X86UNICODE,
+      TARGET_AMD64, // Always Unicode
       TARGET_UNKNOWN,
       TARGETCOUNT = (TARGET_UNKNOWN-TARGETFIRST)
     } TARGETTYPE;
diff --git a/Source/exehead/Ui.c b/Source/exehead/Ui.c
index 323ea0a7..dad7fc49 100644
--- a/Source/exehead/Ui.c
+++ b/Source/exehead/Ui.c
@@ -16,13 +16,12 @@
  * Unicode support by Jim Park -- 08/10/2007
  */
 
+#include "../Platform.h"
 #include <windowsx.h>
 #include <shlobj.h>
 #include <shellapi.h>
 #include <shlwapi.h>
 
-#include "../Platform.h"
-
 #include "resource.h"
 
 #include "fileform.h"
@@ -65,15 +64,15 @@ static void NSISCALL outernotify(int delta) {
 }
 
 #ifdef NSIS_CONFIG_VISIBLE_SUPPORT
-BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
 static int CALLBACK WINAPI BrowseCallbackProc(HWND hwnd, UINT uMsg, LPARAM lParam, LPARAM lpData);
 #ifdef NSIS_CONFIG_LICENSEPAGE
-static BOOL CALLBACK LicenseProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK LicenseProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
 #endif
-static BOOL CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
-static BOOL CALLBACK SelProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
-static BOOL CALLBACK InstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
-static BOOL CALLBACK UninstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK SelProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK InstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
+static INT_PTR CALLBACK UninstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
 #endif//NSIS_CONFIG_VISIBLE_SUPPORT
 
 static DWORD WINAPI install_thread(LPVOID p);
@@ -119,7 +118,7 @@ static void NSISCALL NotifyCurWnd(UINT uNotifyCode)
 
 #ifdef NSIS_CONFIG_ENHANCEDUI_SUPPORT
 #define HandleStaticBkColor() _HandleStaticBkColor(uMsg, wParam, lParam)
-static BOOL NSISCALL _HandleStaticBkColor(UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR NSISCALL _HandleStaticBkColor(UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if ((uMsg - WM_CTLCOLOREDIT) <= (WM_CTLCOLORSTATIC - WM_CTLCOLOREDIT))
   {
@@ -151,7 +150,7 @@ static BOOL NSISCALL _HandleStaticBkColor(UINT uMsg, WPARAM wParam, LPARAM lPara
         c->bkb = CreateBrushIndirect(&lh);
       }
 
-      return (BOOL)c->bkb;
+      return (INT_PTR)c->bkb;
     }
   }
   return 0;
@@ -464,7 +463,7 @@ static int CALLBACK WINAPI BrowseCallbackProc(HWND hwnd, UINT uMsg, LPARAM lPara
   return 0;
 }
 
-BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if (uMsg == WM_INITDIALOG || uMsg == WM_NOTIFY_OUTER_NEXT)
   {
@@ -738,7 +737,7 @@ DWORD CALLBACK StreamLicenseRTF(DWORD_PTR dwCookie, LPBYTE pbBuff, LONG cb, LONG
 }
 #endif
 
-static BOOL CALLBACK LicenseProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK LicenseProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   page *m_this_page=g_this_page;
   HWND hwLicense;
@@ -847,7 +846,7 @@ static BOOL CALLBACK LicenseProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM
 #endif
 
 #ifdef NSIS_CONFIG_UNINSTALL_SUPPORT
-static BOOL CALLBACK UninstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK UninstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if (uMsg == WM_INITDIALOG)
   {
@@ -909,7 +908,7 @@ static int NSISCALL _sumsecsfield(int idx)
 
 #define sumsecsfield(x) _sumsecsfield(SECTION_OFFSET(x))
 
-static BOOL CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   static int dontsetdefstyle;
   page *thispage = g_this_page;
@@ -1279,7 +1278,7 @@ static DWORD WINAPI newTreeWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM l
   return CallWindowProc(oldTreeWndProc,hwnd,uMsg,wParam,lParam);
 }
 
-static BOOL CALLBACK SelProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK SelProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   const int wParamSelChangeNotifyInstTypeChanged = -1;
   static HTREEITEM *hTreeItems;
@@ -1636,7 +1635,7 @@ static DWORD WINAPI install_thread(LPVOID p)
 
 #ifdef NSIS_CONFIG_VISIBLE_SUPPORT
 
-static BOOL CALLBACK InstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+static INT_PTR CALLBACK InstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   HWND linsthwnd=insthwnd;
   if (uMsg == WM_INITDIALOG)
@@ -1724,24 +1723,14 @@ static BOOL CALLBACK InstProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
       HMENU menu = CreatePopupMenu();
       POINT pt;
       AppendMenu(menu,MF_STRING,1,GetNSISStringTT(LANG_COPYDETAILS));
-      if (lParam == ((UINT)-1))
+      pt.x = GET_X_LPARAM(lParam), pt.y = GET_Y_LPARAM(lParam);
+      if (lParam == ((UINT)-1)) // BUGBUG64?
       {
         RECT r;
-        GetWindowRect(linsthwnd, &r);
-        pt.x = r.left;
-        pt.y = r.top;
+        GetWindowRect(linsthwnd,&r);
+        pt.x = r.left, pt.y = r.top;
       }
-      else
-      {
-        pt.x = GET_X_LPARAM(lParam);
-        pt.y = GET_Y_LPARAM(lParam);
-      }
-      if (1==TrackPopupMenu(
-        menu,
-        TPM_NONOTIFY|TPM_RETURNCMD,
-        pt.x,
-        pt.y,
-        0,hwndDlg,0))
+      if (1==TrackPopupMenu(menu,TPM_NONOTIFY|TPM_RETURNCMD,pt.x,pt.y,0,hwndDlg,0))
       {
         int i,total = 1; // 1 for the null char
         LVITEM item;
diff --git a/Source/exehead/fileform.c b/Source/exehead/fileform.c
index 2d3dcb48..ba655f67 100644
--- a/Source/exehead/fileform.c
+++ b/Source/exehead/fileform.c
@@ -83,7 +83,7 @@ static int NSISCALL calc_percent()
 
 #ifdef NSIS_CONFIG_VISIBLE_SUPPORT
 #if defined(NSIS_CONFIG_CRC_SUPPORT) || defined(NSIS_COMPRESS_WHOLE)
-BOOL CALLBACK verProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+INT_PTR CALLBACK verProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if (uMsg == WM_INITDIALOG)
   {
@@ -99,13 +99,11 @@ BOOL CALLBACK verProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 #else
     TCHAR *msg=_LANG_VERIFYINGINST;
 #endif
-
     wsprintf(bt,msg,percent);
-
     my_SetWindowText(hwndDlg,bt);
     my_SetDialogItemText(hwndDlg,IDC_STR,bt);
   }
-  return 0;
+  return FALSE;
 }
 
 DWORD verify_time;
@@ -460,8 +458,8 @@ static char _inbuffer[IBUFSIZE];
 static char _outbuffer[OBUFSIZE];
 extern int m_length;
 extern int m_pos;
-extern BOOL CALLBACK verProc(HWND, UINT, WPARAM, LPARAM);
-extern BOOL CALLBACK DialogProc(HWND, UINT, WPARAM, LPARAM);
+extern INT_PTR CALLBACK verProc(HWND, UINT, WPARAM, LPARAM);
+extern INT_PTR CALLBACK DialogProc(HWND, UINT, WPARAM, LPARAM);
 static int NSISCALL __ensuredata(int amount)
 {
   int needed=amount-(dbd_size-dbd_pos);
diff --git a/Source/exehead/fileform.h b/Source/exehead/fileform.h
index 562a0b0b..9b30720a 100644
--- a/Source/exehead/fileform.h
+++ b/Source/exehead/fileform.h
@@ -468,6 +468,7 @@ typedef struct
 #define CC_BK_SYS 8
 #define CC_BKB 16
 
+#pragma pack(push, 4)
 typedef struct {
   COLORREF text;
   COLORREF bkc;
@@ -476,6 +477,7 @@ typedef struct {
   int bkmode;
   int flags;
 } ctlcolors;
+#pragma pack(pop)
 
 // constants for myDelete (util.c)
 #define DEL_DIR 1
diff --git a/Source/script.cpp b/Source/script.cpp
index dca3b467..68a565ba 100644
--- a/Source/script.cpp
+++ b/Source/script.cpp
@@ -877,8 +877,8 @@ int CEXEBuild::includeScript(const TCHAR *f, NStreamEncoding&enc)
 {
   NIStream incstrm;
   const bool openok = incstrm.OpenFileForReading(f,enc);
-  if ( // !include defaults to UTF-8 after "Unicode true" 
-    NStreamEncoding::AUTO == enc.GetCodepage() && build_unicode && 
+  if (NStreamEncoding::AUTO == enc.GetCodepage() && // !include defaults to UTF-8 after "Unicode true" 
+    build_unicode && !enc.IsUnicodeCodepage(enc.GetPlatformDefaultCodepage()) &&
     enc.GetPlatformDefaultCodepage() == incstrm.StreamEncoding().GetCodepage()
   ) incstrm.StreamEncoding().SetCodepage(NStreamEncoding::UTF8);
   enc = incstrm.StreamEncoding();