Hi Gavin, [ If you rename the .i file as a .cpp you can then add it to your project and right-click-Compile it individually. If it still shows the original line numbers then generate the .i file again but turn on the "Preprocess Suppress Line Numbers" setting as well. ] I compiled just that one file(after making changes to log preprocessor output to file). Replaced the contents of the same file by the contents of the .i file and tried compiling again and I get lot of errors as follows. Looks like I am doing something wrong. ------ Build started: Project: Worker, Configuration: Debug Win32 ------ Compiling... cl : Command line warning D9007 : '/C' requires '/E, /EP or /P'; option ignored manager_abc.cpp c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2042) : error C2011: 'localeinfo_struct' : 'struct' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2042) : see declaration of 'localeinfo_struct' c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2048) : error C2011: 'tagLC_ID' : 'struct' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2048) : see declaration of 'tagLC_ID' c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2057) : error C2011: 'threadlocaleinfostruct' : 'struct' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\crtdefs.h(2057) : see declaration of 'threadlocaleinfostruct' c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(561) : error C2011: 'std::_Lockit' : 'class' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(561) : see declaration of 'std::_Lockit' c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(708) : error C2011: 'std::_Mutex' : 'class' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(708) : see declaration of 'std::_Mutex' c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(760) : error C2011: 'std::_Init_locks' : 'class' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\yvals.h(760) : see declaration of 'std::_Init_locks' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(59) : error C2011: '_iobuf' : 'struct' type redefinition c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(59) : see declaration of '_iobuf' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(269) : error C2995: 'char *gets_s(char (&)[_Size])' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(269) : see declaration of 'gets_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(307) : error C2995: 'int _snprintf_s(char (&)[_Size],size_t,const char *,...)' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(307) : see declaration of '_snprintf_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(309) : error C2995: 'int sprintf_s(char (&)[_Size],const char *,...)' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(309) : see declaration of 'sprintf_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(326) : error C2995: 'errno_t tmpnam_s(char (&)[_Size])' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(326) : see declaration of 'tmpnam_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(336) : error C2995: 'int _vsnprintf_s(char (&)[_Size],size_t,const char *,va_list)' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(336) : see declaration of '_vsnprintf_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(342) : error C2995: 'int vsprintf_s(char (&)[_Size],const char *,va_list)' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(342) : see declaration of 'vsprintf_s' c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(422) : error C2995: 'wchar_t *_getws_s(wchar_t (&)[_Size])' : function template has already been defined c:\program files (x86)\microsoft visual studio 8\vc\include\stdio.h(422) : see declaration of '_getws_s' ...and so on... Thanks, Ram