Windows Server 2012 R2

Windows Server 2012 R2, codenamed "Windows Server Blue", is the tenth major version of the Windows NT operating system produced by Microsoft to be released under the Windows Server brand name. It was unveiled on June 3, 2013, at TechEd North America, and released on October 17 of the same year. It is the successor to Windows Server 2012, and is based on the Windows 8.1 codebase. It is the final version of Windows Server to use the "R2" suffix, which had been used since the release of Windows Server 2003 R2. It removed support for processors without CMPXCHG16b, PrefetchW, LAHF and SAHF. A further update, formally designated Windows Server 2012 R2 Update, was released in April 2014. It is a cumulative set of security, critical and other updates. Windows Server 2012 R2, like previous versions of Windows Server before it and versions after it, is only compatible with 64-bit processors. It was succeeded by the Windows 10-based Windows Server 2016. Mainstream support ended on October 9, 2018, and extended support ended on October 10, 2023. It is eligible for the paid Extended Security Updates (ESU) program, which offers continued security updates until October 13, 2026.