For more information about the Windows port, see http://www.iki.fi/tml/gimp/win32/ . As for now, only Microsoft C is really supported. Before compiling, check the BIN definition in makefile.msc. Compile with `nmake -f makefile.msc`. Install with `nmake -f makefile.msc install`. Gnu-Win32 with egcs and maybe LCC-Win32 support will be added later.