I guess its my turn to play "Microsoft Defender". There are two separate lineages to Windows. The DOS/Windows lineage and the Windows NT lineage.
1/ Windows 1.0
2/ Windows 2.0
3/ Windows 3.x
4/ Win95, Win98/98SE and WinME
One might try to claim Win98 and WinME were versions 5 and 6 but they were not in my opinion big enough jumps to qualify.
Windows 7 is part of the Window NT lineage.
1/ Windows NT 1.0
2/ There was no WinNT 2 they skipped it to bring the numbers to match the Windows 3.1
3/ Windows NT 3.1/3.5
4/ Windows NT 4.x
5/ Windows 2000/XP
6/ Windows Vista
7/ Windows 7
Windows MCE, 2003, 2008 are server variants of the Windows NT version of the same time frame not additional versions of the mainstream. Windows 2003 would be Windows XP - Server (or Windows NT 5 Server if you prefer) as an example.
Go to Windows Explorer. Open the Help menu, choose about Windows and see the version #.
Um.. there is Win XP Server Edition 64 bit.. as well as server 2003 32 bit and 64 bit... both are based on the NT structure as is Vista, Windows 7 2K8, and 2K.
But going back to XP .. it is much like Vista as far as the editions go.
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, for business and power users (Version number: NT 5.1.2600)
Windows XP Professional 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 x86-64 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. There are five versions:
Windows XP Media Center Edition 2001
Windows XP Media Center Edition 2002
Windows XP Media Center Edition 2003 (MCE 2002 Roll Up pack 1)
Windows XP Media Center Edition 2004 (MCE 2002 Roll Up Pack 2)
Windows XP Media Center Edition 2005
Windows XP 64-bit Server 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'.
Windows XP Tablet PC Edition, for tablet PCs
Windows XP Embedded, for embedded systems requiring parts of the Windows XP infrastructure
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.
Windows Vista, for home and business desktops and portable computers
Windows Vista Starter Much like Windows XP Starter Edition, this edition will be limited to emerging markets such as Colombia, India, Thailand, and Indonesia, mainly to offer a legal alternative to using unauthorized copies. It will not be available in the United States, Canada, Europe, or Australia. (x86 only)
Windows Vista Home Basic Similar to Windows XP Home Edition, Home Basic is intended for budget users not requiring advanced media support for home use. The Windows Aero theme with translucent effects will not be included with this edition. (x86 only)
Windows Vista Home Premium Like Windows XP Media Center Edition, this edition will support more advanced multimedia and entertainment authoring, premium games, mobile and tablet PC support, Network Projector, Windows Aero, Touch Screen, and auxiliary display (via Windows Side Show) support. (x86 & x64)
Windows Vista Business Comparable to Windows XP Professional and Windows XP Tablet PC Edition, Windows Vista Business Edition is aimed at the business market. Includes all the features of Home Premium with the exception of Windows Media Center and related technologies, Parental Controls, and Windows DVD and Movie Maker HD. (x86 & x64)
Windows Vista Enterprise (Microsoft Windows NT 6.0.6000.0) This edition is aimed at the enterprise segment of the market, and is a superset of the Business edition. Additional features include multilingual user interface support, BitLocker Drive Encryption, and UNIX application support. This edition will not be available through retail or OEM channels (x86 & x64)
Windows Vista Ultimate This edition combines all the features of the Home Premium and Enterprise editions, a game performance tweaker (WinSAT), and "Ultimate Extras". On January 7, 2007, at CES, Microsoft began to announce what some of these Ultimate Extras will be. (x86 & x64)
Server 2K8 is basically Vista Server Edition (x86 & x64)
Going back to XP, XP is a cross platform.. it integrated 98 SE and server 2k.
Win XP MCE is not a Server Edition.. MCE is Windows XP Professional 32 bit Media Center Edition .. and there are 3 versions of this released.. MCE 2001, 2002, and 2005... MCE 2003 and 2004 are just roll up packs to MCE 2002, so do not count as actual OS releases.. However MCE 2001 could onlt roll up with an actual purchase of the MCE 2002 or 2005 upgrade package .. same for MCE 2002, 2003, 2004 to upgrade to MCE 2005.. a separate purchase to upgrade. so in essance there wre 3 versions of MCE released.
Win ME was MS first attempt to strip Dos from the OS, which is why if failed.. in Win 2K, MS emulates DOS though the OS.. there is no native DOS mode in any MS OS from ME and newer. Win 98 SE was the last MS OS to have native DOS support, not emulated.