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