After an abundance of rumors, whispers, and slip-ups in job postings, we now have more concrete evidence of Microsoft's secretive Windows Blue operating system: An honest-to-goodness leak of an early build of the OS.
The leak of "Windows Build 9364" appeared on torrent and file sharing sites Sunday morning in the form of a 2.6GB ISO file, and news of the leak blazed across the Net like wildfire after an initial appearance on Windows 9 Beta. Although Microsoft hasn't issued a formal statement about the leak, it's been dissected hands-on by WinSuperSite and numerous forum-goers, and Build 9364 appears to a 100 percent legitimate (and 100 percent unauthorized) look at the future of Windows.
Source
A Guy