c:\OldOs\OSHistory\ 
DOS is great! Read about its origins!

OS/2 is great! Read about its origins.

Windows 1.x History

Windows 2.x History and Origins

History of Windows 3.1 and variants

Windows 98, and ME – the operating systems of the late 90s and early 200s.

Windows NT 3.1 - Microsoft’s first foray into non-DOS kernels.

Windows NT 5 - moving into the future

Clippy’s best friend and grandfather – Microsoft Bob