Windows Vista

Windows Vista was released on November 30, 2006 to business customers, consumer versions following on January 30, 2007. Windows Vista intended to have enhanced security by introducing a new restricted user mode called User Account Control, replacing the "administrator-by-default" philosophy of Windows XP. One major difference between Vista and earlier versions of Windows, Windows 95 and later, is that the original start button was replaced with just the Windows icon. Vista also features new graphics features, the Windows Aero GUI, new applications (such as Windows Calendar, Windows DVD Maker and some new games including Chess, Mahjong, and Purble Place),[8] Internet Explorer 7, Windows Media Player 11, and a large number of underlying architectural changes.
Windows Vista ships in six editions:[9]
Starter (only available in developing countries)
Home Basic
Home Premium
Business
Enterprise (only available to large businesses and enterprises)
Ultimate (combines both Home Premium and Enterprise)
All editions (except Starter edition) are currently available in both 32-bit and 64-bit versions. The biggest advantage of the 64-bit version is breaking the 4 gigabyte memory barrier, which 32-bit computers cannot fully access.