Windows Vista

Windows Vista is an operating system by Microsoft. It was released worldwide on 2007-01-30. It succeeds Windows XP and was replaced by Windows 7. It reached RTM on 2006-11-08.

Editions
Windows Vista came in many editions. Unlike Windows XP, there was no special edition for Media Center and 64-bit capability. Windows Vista also did not have an embedded version.
 * Starter This edition is intended for emerging markets and low-cost PC's. As in XP, the 3-program limit was there , and only 1GB RAM was accepted. Other software restrictions applied as well. This version is hence not available in 64-bit.
 * Home Basic Found in low cost to mid-end, this version of Windows Vista does not fully have Aero(though it has DWM) , and hence does not have effects like transparency and 3D Flip. Windows Media Center is not included as well. Parental Controls is included however. However , it does not have the hardware and 3-program limit as Starter.
 * Home Premium The mid end of Windows Vista, this version includes full Aero and Windows Media Center. It also includes Premium Games(eg - Inkball).
 * Business The business oriented version of Windows Vista, it contains several features like full RDP(client/host) capability , Group Policy and domain join ability. However , Windows Media Center is not included , Parental Controls is not included , and Premium Games are disabled by default.
 * Ultimate The top consumer variant of Windows Vista, it is a merge of the features containing on Windows Vista Home Premium and Business. Bitlocker is included in this version.
 * Enterprise The top business variant of Windows Vista. It is like Ultimate, but without Windows Media center and includes enterprise-specific tools.

Note that certain features(like Aero or TV support) may require premium/different/upgraded hardware and so may not be available on all PCs's.