You also left out Windows Server 2003....But heck, who cares? Its a crappy one anyways just like Windows ME....Just to familiarize people;-Windows 2000 = Windows NT 5.0, corresponding server software is IIS 5.0Windows XP = Windows NT 5.1, corresponding server software is IIS 5.1, but it is not recommended to set up a server on a Windows XP machine.Windows Server 2003 = Windows NT 5.2, corresponding server software is IIS 6.0.IIS 4.0 for Windows 98 was also known as Microsoft Personal Web Server 98, V4.0.There was a version of Windows called Windows 97, but it was only available illegally as it was a early leak of Windows 98, and at that time Microsoft was expecting a '97 release so they named it Windows 97 at that time...