This is a listing of the versions of the operating systems offered by Microsoft as Windows.

Current versions

• Windows CE for embedded systems including Consumer Electronics products (note: CE is a different operating system from DOS and Windows NT/2000/XP, and Microsoft makes the source code available)
  • Windows Mobile for smart phones and PDAs (a version of Windows CE)
    • Portable Media Center for Digital Media Players
• Windows XP for desktops and laptops (notebooks)
  • Windows XP Starter Edition, for new computer users in developing countries
  • Windows XP Home Edition, for home desktops and laptops
  • Windows XP Home Edition N, as above, but without a default installation of Windows Media Player, as mandated by an EU ruling
  • Windows XP Professional Edition, for business and power users (Version number: NT 5.1.2600)
  • Windows XP Professional Edition N, as above, but without a default installation of Windows Media Player, as mandated by an EU ruling
  • Windows XP Professional x64 Edition, for PCs with 64-bit processors (based on Windows Server 2003)
  • Windows XP Tablet PC Edition, for notebooks with a touch screen or a pen-sensitive screen
  • Windows XP Media Center Edition for desktops and notebooks with an emphasis on audio, video, and PVR capability
• Windows Server 2003 for servers
  • Small Business Server for first server installations (up to 2 processors)
  • Web Edition for basic Web serving (up to 2 processors)
  • Standard Edition for smaller server applications that don't require clustering (up to 4 processors)
  • Enterprise Edition for larger server applications, and clustering (up to 8 processors)
  • Datacenter Edition for mainframe like servers (up to 128 processors)
  • Storage Server for Network Attached Storage Devices
• Windows XP Embedded for embedded systems
• Windows Fundamentals for Legacy PCs, a low-end version of Windows XP that is intended to be a thin-client that works with older hardware.

Past versions

• DOS-Based
  • 1985 November - Windows 1.0
  • 1987 December 9 - Windows 2.0
  • 1990 May 22 - Windows 3.0
  • 1992 August - Windows 3.1
  • 1992 October - Windows for Workgroups 3.1
  • 1993 November - Windows for Workgroups 3.11
  • 1995 August 24 - Windows 95 (Version number: 4.00.950)
  • 1998 June 25 - Windows 98 (Version number: 4.1.1998)
  • 1999 May 5 - Windows 98 Second Edition (Version number: 4.1.2222)
  • 2000 June 19 - Windows Me (Version number: 4.9.3000)
• NT Kernel-Based
  • 1993 August - Windows NT 3.1
  • 1994 September - Windows NT 3.5
  • 1995 June - Windows NT 3.51 (Version number: NT 3.5.1057)
  • 1996 July 29 - Windows NT 4.0 - the last version which ran on RISC architectures like DEC Alpha, MIPS and PowerPC. Later versions concentrated on x86-based hardware and - mainly as server OSs - the IA-64 line of CPUs. (Version number: NT 4.0.1381)
  • 2000 February 17 - Windows 2000 (Version number: NT 5.0.2195)
  • 2001 October 25 - Windows XP 64-bit Edition - A version of Windows XP roughly analogous to Windows XP Professional for Intel's IA-64 (Itanium) line of CPUs. It was discontinued in early 2005 after manufacturers stopped shipping Itanium systems marketed as 'workstations'.

Cancelled versions

• 1991-1998 - Cairo (a "true object-oriented OS") planned after Windows NT
• 1996 May 3 - Windows Nashville (Windows 96) (cancelled) (Became Windows 95B.)
• 1999 December - Windows Neptune was sent out to beta testers but was never released. Should have been a consumer version (i.e. home edition) of Windows 2000.

Future versions

• November 2006 - Windows Vista (previously known by its codename Longhorn) is scheduled to be released for business customers.
• January 2007 - The home editions of Windows Vista are scheduled to be released.
• 2007 - Windows Server "Longhorn" (probably Windows Server 2007; announced to continue the year-based naming scheme and estimated for 2007.)
• ??? - Windows "Vienna" (formerly known as Blackcomb), slated to be Vista's successor.
• ??? - Windows XP "Mönch" Aimed at companies that want to better secure their older machines.

See also

• List of Microsoft software codenames