Windows is an operating system created by Microsoft to provide a graphical user interface when using the computer. Every few years Microsoft comes out with a new version of windows.
Some version of Windows listed in chronological order:
Windows 3.0, 3.1
Windows NT 3.5 Server
Windows 95
Windows NT 4.0 Server
Windows 98
Windows 2000 Server
Windows ME
Windows XP
Windows 2003 Server