Windows 7 Starter
Windows 7 Starter is the edition of Windows 7 that contains the fewest features. The Windows Aero theme is not included in this version, and it is not available in a 64-bit variant. The desktop wallpaper, and Visual Style (Windows 7 Basic) is also not user-changeable. This edition is available pre-installed on computers, especially netbooks, through system integrators or computer manufacturers.[10][11][12]

Windows 7 Home Basic
Windows 7 Home Basic is available in emerging markets such as Brazil, People's Republic of China, Colombia, India, Pakistan, the Philippines, Mexico, and Thailand. [13] Also available in Russia. It is not available in first world countries including Western and Central Europe, North America, Australia and Saudi Arabia.[13] Some Aero options are excluded along with several new features.[13] Home Basic, along with other editions sold in emerging markets, include geographical activation restriction, which requires users to activate Windows within a certain region or country.[14]

Windows 7 Home Premium
This edition contains features aimed at the home market segment, such as Windows Media Center, Windows Aero and touch-screen controls.[15]

Windows 7 Professional
This edition is targeted towards enthusiasts and small business users.[16] It includes all the features of Windows 7 Home Premium, and adds the ability to participate in a Windows Server domain.[16] Additional features include operating as a Remote Desktop server, location aware printing, Encrypting File System, Presentation Mode, Software Restriction Policies (but not the extra management features of AppLocker) and Windows XP Mode.[16] Windows 7 Enterprise
This edition targets the enterprise segment of the market and is sold through volume licensing to companies which have a Software Assurance contract with Microsoft.[17] Additional features include support for Multilingual User Interface (MUI) packages, BitLocker Drive Encryption, and UNIX application support.[17] Not available through retail or OEM channels, this edition is distributed through Microsoft Software Assurance (SA).[17] As a result it includes several SA-only benefits, including a license allowing the running of multiple virtual machines, and activation via VLK.[14]

Windows 7 Ultimate
Windows 7 Ultimate contains the same features as Windows 7 Enterprise, but unlike the Enterprise edition, it is available to home users on an individual license basis.[18] Windows 7 Home Premium and Windows 7 Professional users are able to upgrade to Windows 7 Ultimate for a fee using Windows Anytime Upgrade if they wish to do so.[7] Unlike Windows Vista Ultimate, the Windows 7 Ultimate edition does not include the Windows Ultimate Extras feature or any exclusive features.[18]

N Editions
Windows N Editions are available for both upgrades and new purchases, for the Premium, Professional, and Ultimate editions of Windows 7. The features in the N Editions are the same as their equivalent full versions as well as the same price, but do not include Windows Media Player. The cost of the N Editions are the same as the full versions, as Windows Media Player can be downloaded without charge from Microsoft for the N Editions.

VL Builds
VL Builds work with VLKs (Volume License Keys). Volume license keys can be used to activate multiple installations of the software without any mechanism (such as a product activation mechanism) checking the total number of installations. The license for the software will place restrictions on the use of the key. Typically the license will limit the key to a fixed number of installations which must only be within the licensee's organization and also place the licensee under an obligation to keep a record of the number of installations, keep the key confidential and possibly even require that the licensee organization makes itself available for a software licensing audit to verify that its use of the key is within the terms of the license. If a volume license key becomes known and used outside of the organization it is licensed to then this is regarded as copyright infringement.

[edit] Upgrade editions

Windows Vista can be upgraded to Windows 7 with an in-place upgrade if the processor architecture, comparable edition, and language version are the same.[2][7][19] Windows XP can only be upgraded to Windows 7 via a clean install.[2][7][20][21]. However, in some countries, Microsoft has recommended a clean install regardless of whether going from XP or Vista, with reasoning which has not been made clear.[22]
[edit] Standard upgrade editions

Windows 7 supports upgrading from an applicable version of XP, and Vista to an applicable version of Windows 7 via Upgrade Editions. The options mean that users can update freely from any previous version to any of the new three retail editions of Windows 7: Home Premium, Professional, or Ultimate (plus in Europe, and possibly South Korea, these Upgrade Editions also come in optional N versions). Discounted upgrade pricing is only available to current users of XP or Vista.[23]
[edit] Standard upgrade editions (Family Packs)

Windows 7 is available as an Upgrade Family Pack edition in certain markets, to upgrade to Windows 7 Home Premium only. It gives licenses to upgrade three machines from XP (any edition) or Vista (Starter, Home Basic and Home Premium editions only) to the Windows 7 Home Premium edition. These are not full versions, so each machine to be upgraded must have one of these qualifying previous versions of Windows for them to work.[24] In the United States, this offer was discontinued in early December 2009.
[edit] Anytime Upgrade editions

Windows 7 also supports in-place upgrades from a lower edition of Windows 7 to a higher one using the Windows Anytime Upgrade tool.[7] There are currently three retail options available (though it is currently unclear whether they can be used with previous installations of the N versions):[25] Currently, there are no plans for family pack versions of the Anytime Upgrade editions. It's possible to use the Product Key from a Standard upgrade edition to accomplish an in-place upgrade (e.g. Home Premium to Ultimate).

* Starter to Home Premium.
* Home Premium to Professional.
* Professional to Ultimate.
* Home Premium to Ultimate.

Windows 7 Edition comparison chart















source:http://en.wikipedia.org/wiki/Windows_7_editions#cite_note-ExtremeTechProfessional-15