'stdafx' is just the default name for the 'precompiled header directive'. The headers that included in stdafx.h are compiled once, and the information is saved to disk. When a file includes stdafx.h, the compiler just loads the precompiled data instead of re-parsing all the headers. Typically, more times is spent parsing header files than actually compiling your code, so using precompiled headers can dramatically speed up your build times.

Some additions:
stdafx.h is Visual C++ specific pre-compiled headers artifact.
In precompiled headers mode VC++ ignores all lines before #include "stdafx.h". You may switch on/off this mode in Project Properties | Configuration | C/C++ | Precompiled Headers tab.

how do i get to project properties?

There is a wonderful thing in VS IDE: the Main Menu (look at the top of the VS window). Select Project | projectname Properties or simply press Alt+F7 (if you can cope with a keyboard ;))...

Yeah, really now. Look i had a brain fade, im not a complete idiot. Found it, thanks for your info, it is very useful.

Cheers

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