Well, Windows isnt the only OS...

But...heres a timeline for Windows, from first to last:

Windows 1.0
Windows/286
Windows 3.0
Windows 3.1
Windows NT 3.51
Windows 95
Windows NT 4.0
Windows 98
Windows 2000
Windows ME
Windows XP
Windows 2003

I have copies of each, except 2003. Kthxbye.