#define OS_DOS 0   //MS-DOS
#define OS_WIN 1   //Windows 3.1x
#define OS_WIN95 2 //Windows 95/NT 4.0
#define OS_WINNT 3 //Windows NT 3.x
#define OS_OS2 4   //OS/2    (not detected yet)
#define OS_DV 5    //Desqview