Windows 7 Home Premium SP1 - 64 bit

Windows 7 is a personal computer operating system developed by Microsoft. It is a part of Windows NT family of operating systems. Development of Windows 7 started as early as 2006 under the codename "Blackcomb." Windows 7 was released to manufacturing on July 22, 2009,[8] and became generally available on October 22, 2009,[9] less than three years after the release of its predecessor, Windows Vista. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time.