Windows 7

Windows 7 (previously codenamed Blackcomb and Vienna) is scheduled to be the next major version of Microsoft Windows, expected to be the successor of Windows Vista.^[1] Microsoft has announced that it is "scoping Windows 7 development to a three-year timeframe", and that "the specific release date will ultimately be determined by meeting the quality bar."^[2] The client versions of Windows 7 will ship in both 32-bit and 64-bit versions,^[2] even though the server counterpart (which will succeed Windows Server 2008) will be exclusively 64-bit.

SOURCE :- WIKI