Sets whether install logging to $INSTDIR\\install.log will happen. $INSTDIR must have a value before you call this function or it will not work. Note that \e{NSIS_CONFIG_LOG} must be set in the compile configuration file (config.h) on compile time (it is not by default) to support this. See \R{compiling_infos}{Compiling NSIS Sources} for more information about recompiling NSIS.