Following is a brief summary of the client versions of Windows (a user's PC running Windows). For more on the server versions, see
Windows Server 2003,
Windows Server 2008 and
Windows Server 2012.
Windows NT Lineage (32 & 64 bit)
Starting in the 1990s, Windows NT ushered in a new architecture that has been carried forward more or less intact ever since.
Windows 11 (2021)
Current client version of Windows. Windows is a 64-bit OS and runs only on 64-bit processors. however, it does support 32-bit Windows applications but not 16-bit DOS programs. See
Windows 11.
Windows 10 S (2017)
Streamlined version that obtains content via the Internet. See
Windows 10 S.
Windows 10 (2015) - MS Version 6.4
Previous client version of Windows. See
Windows 10.
Windows 8/8.1 (2012-2013) - MS Version 6.2/6.3
The previous client version of Windows. See
Windows 8.
Windows 7 (2009) - MS Version 6.1
A client version of Windows. Windows 7 greatly improved stability over Vista. See
Windows 7.
Windows Vista (2006) - MS Version 6.0
A client version of Windows that was widely criticized for its bugs and behavior (see
Windows Vista). Windows Server 2008 was the server counterpart. See
Windows Server 2008.
Windows XP (2001) - MS Version 5.1
A client version of Windows that was widely used. Adding more security and administrative capabilities, XP became available in 64-bit versions for AMD x86 and Intel Itanium CPUs. See
Windows XP.
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. Windows 2000 came in one workstation and three server versions. Server versions supported 64-bit AMD x86 and Intel Itanium CPUs. See
Windows 2000.
Windows NT (1993) - MS Versions 3.1, 3.5, 4.0
Windows NT 3.1 was a completely new 32-bit OS with separate client and server versions. Introduced during the reign of Windows 3.1 and two years before Windows 95, it used the same Program Manager user interface as Windows 3.1, but provided greater stability. In 1996, Windows NT 4.0 switched to the Windows 95 Start menu interface, but did not include Plug and Play. NT Server gained significant market share, while NT Workstation client version was aimed at the professional user and not the Windows 95/98 market. See
Windows NT.
Windows 95 Lineage (32 bit)
Windows 95 was the first Windows operating system that launched on its own and did not require DOS to be running.
Windows ME (2000) - MS Version 4.9
An upgrade to Windows 98. ME had a shorter boot time, but no longer could be booted into DOS only (DOS sessions could still be run in a Windows window). See
Windows ME.
Windows 98 (1998) - MS Version 4.1
Windows 98 was an upgrade to Windows 95 that tightly integrated the Internet Explorer Web browser with the OS. In 1999, Windows 98 Second Edition fixed numerous bugs and upgraded its applications. See
Windows 98 and
Windows Second Edition.
Windows 95 (1995) - MS Version 4.0
Windows 95 was the first 32-bit Windows operating system and a major upgrade from Windows 3.1. It used an entirely different user interface that incorporated the now-common Start menu and Taskbar. It was also the first time the computer booted directly into Windows, rather than being loaded after booting up in DOS. See
Windows 95.
Windows DOS Lineage (16 bit)
Windows from Version 1.0 to 3.1 all required DOS to be running before they were launched.
Windows 3.x (1990-1992) - MS Version 3.x
Windows 3.0 was the first popular version of Windows with a new, colorful user interface that was far superior to Windows 2.0. Although the PC still booted into DOS, Windows 3.0 included a DOS extender that broke the 1MB memory limit (a major breakthrough). Windows 3.0 was widely used to multitask DOS applications.
Windows 3.1 (1992) was more stable and faster. It evolved into Windows for Workgroups (Version 3.11), which added peer-to-peer networking and was the last 16-bit Windows version. See
Windows 3.0 and
Windows 3.1.
Windows 2.0/286/386 (1987) - MS Version 2.0
Windows 2.0 introduced overlapping, resizable windows with more flexibility. Soon after, Windows/386 was released for Intel's 386 CPU, which could run multiple DOS applications simultaneously (Windows 2.0 was renamed Windows/286). Windows was becoming more useful, and a handful of companies adopted it as an operating environment. See
Windows 2.0.
Windows 1.0 (1985) - MS Version 1.0
The first Windows version introduced the "MS-DOS Executive," which was a DOS application that ran applications in side-by-side windows. It was rarely used. See
Windows 1.0.
Windows Word
Client Size Year
Versions (bits) Intro
NT Lineage
11 64 2021
10 S 32/64 2017
10 32/64 2015
8.1 32/64 2013
8 32/64 2012
7 32/64 2009
Vista 32/64 2006
XP 32/64 2001
2000 32 2000
NT 32 1993
95 Lineage
ME 32 2000
98 32 1998
95 32 1995
DOS Lineage
3.11** 16 1992
3.1 16 1992
3.0 16 1990
386 16 1987
2.0 16 1987
1.0 16 1985
** 1st version to have
built-in networking
Windows Word
Server Size Year
Versions (bits) Intro
NT Lineage
Server 2016 64 2016
Server 2012 64 2012
Server 2008 32/64 2008
Server 2003 32/64 2003
Server 32/64 2000