Windows Server 2008 R2, codenamed "Windows Server 7", is the fifth version of the Windows Server operating system produced by Microsoft and released as part of the Windows NT family of operating systems. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009, shortly after the completion of Windows 7. It is the successor to Windows Server 2008, which is derived from the Windows Vista codebase, released the previous year, and was succeeded by the Windows 8-based Windows Server 2012. Enhancements in Windows Server 2008 R2 include new functionality for Active Directory, new virtualization and management features, version 7.5 of the Internet Information Services web server and support for up to 256 logical processors. It is built on the same kernel used with the client-oriented Windows 7, and is the first server operating system released by Microsoft not to support 32-bit processors, a move which was followed by the consumer-oriented Windows 11 in 2021. Windows Server 2008 R2 has 32-bit software support and is the last version of Windows Server to support Itanium processors; its successor, Windows Server 2012, supports x64 processors only. Seven editions of Windows Server 2008 R2 were released: Foundation, Standard, Enterprise, Datacenter, Web, HPC Server and Itanium, as well as Windows Storage Server 2008 R2. A home server variant called Windows Home Server 2011 was also released.