Introduction: The End of an Era, The Persistence of an ISO In the annals of enterprise IT, few operating systems have commanded the respect and longevity of Windows Server 2008 R2 . Released in 2009, it was the first Microsoft server OS to be offered exclusively in 64-bit (x64) architecture, leaving its 32-bit predecessor (non-R2) behind. For nearly a decade, it powered critical infrastructure—from domain controllers and file servers to SQL databases and terminal services.