DR DOS 6.0 1991 Digital Research MS-DOS (Version 5.00) 1991 Microsoft MS-DOS (Version 6.00) 1992 Microsoft MS-DOS (Version 6.22) 1994 Microsoft Novell DR Multiuser DOS Release 5.1 1992 Novell Novell DOS 7 1994 Novell PC DOS (Version 6.3) 1993 IBM IBM PC DOS 2000 1998 IBM Microsoft Windows Version 3.0 1990 Microsoft Windows Version 3.1 1992 Microsoft