1980 Seattle Computer Products develops 86-DOS or QDOS
1981 PC-DOS and MS-DOS 1.0
1982 MS-DOS 2.0
1984 MS-DOS 3.0
1984 3.1 Local area network support
1985 Windows 1 Runs on top of DOS (not popular)
1986 MS-DOS 3.2 supports Expanded Memory Specification (EMS) and Expanded Memory Manager (EMM)
1987 Windows 2 (Excel and Word for Windows)
1988 MS-DOS 4.0
1990 Windows 3 The first popular version of windows
 Intel processor upgrades force DOS upgrades to keep up.
1991 MS-DOS 5.0
1993 MS-DOS 6.0
1995 MS-DOS 7.0
1995 Windows 95 - Long filename (LFN) (255 UTF-16 character) support.
       Previous file names were limited to 8.3 (8 character name + 3 char. extension)
1996 Windows NT (New Technology) replaces DOS as underlying OS
   processor-independent, multiprocessing, multi-user 32-bit operating system
1998 Windows 98 (DOS based)
2000 MS-DOS 8.0
2000 Windows 2000 (NT 5)
2000 Windows ME (last DOS based version)
2001 Windows XP
2006 Windows Vista
2007 Windows 7
2012 Windows 8 
     Designed to make it easier for touchscreen users to use Windows.
     With more smart phone/tablet features