Predefined Versions : Windows and Win32

[Elrood]

	  Win32
	/
Windows
	\
	  Win64

Since there is no Win64 version for DMD (and this probably will not
change for quite some time) version(Windows) and version(Win32) are
pretty much interchangable. Unless your code is win32-specific, you
should nonetheless use version(Windows) to be future-proof, for
alternative compilers such as LDC and GDC, which will probably support
64bit Windows sooner than DMD, and just generally to do it right.