Why Exchange Server 2007 SP2 doesn't run on Windows Server 2008 R2?

Microsoft released Exchange Server 2007 SP2 with support on Windows Server 2003 SP2, Windows Server 2003 R2 SP2 and Windows Server 2008 SP2 but not Windows Server 2008 R2, due to two primary technical points: “First, Windows Server 2008 R2, while an incremental OS upgrade, creates significant testing requirements for Exchange 2007. Because the Exchange 2007 […]

Microsoft released Exchange Server 2007 SP2 with support on Windows Server 2003 SP2, Windows Server 2003 R2 SP2 and Windows Server 2008 SP2 but not Windows Server 2008 R2, due to two primary technical points: “First, Windows Server 2008 R2, while an incremental OS upgrade, creates significant testing requirements for Exchange 2007. Because the Exchange 2007 SP2 engineering preceded the Windows Server 2008 R2 RTM, Exchange 2007 SP2 would have had to be delayed significantly to align testing schedules.  Second, because upgrading the server OS underneath an existing Exchange server is not supported, the feedback we have received is that the primary need is to support Windows Server 2008 R2 domain controllers in an existing Exchange 2007 deployment, which we have done,” Exchange team.