Question: what are the different types of windows operating systems?
Answer: MS-DOS - Microsoft Disk Operating System (1981) ... 
Windows 1.0 – 2.0 (1985-1992) ... 
Windows 3.0 – 3.1 (1990–1994) ... 
Windows 95 (August 1995) ... 
Windows 98 (June 1998) ... 
Windows ME - Millennium Edition (September 2000) ... 
Windows NT 31. ... 
Windows 2000 (February 2000)