Q: (from Shawn)
Will Exchange 2010 work on Windows Server 2003 R2?
It appears my initial guess of “No” was right:
Operating system―Microsoft Windows Server 2008 x64 Standard and Enterprise Edition with Service Pack 2 or Microsoft Windows Server 2008 R2 Standard and Enterprise Edition.
From the Exchange, Product Information, Product Details, System Requirements page:
I’m guessing it’s not as much an OS issue since Windows Server 2003 R2 did come in a 64bit edition as it is an Active Directory issue.