Available in client and server versions, Windows NT included built-in networking and preemptive multitasking. NT was introduced in 1993 as Version 3.1 with the same user interface as Windows 3.1 ...
Windows 2000 (2000) - MS Version 5.0 Windows 2000 was an updated version of Windows NT 4 for client and server. It added numerous enhancements including Plug and Play and Active Directory.