One question that is filling the forums right now is “What is wrong with Exchange 2007 SP2 in a 2008 R2 Domain?”
When Exchange 2007 SP2 was released, Microsoft stated that it will support Windows 2008 R2 domain controller, but you can’t install Exchange 2007 SP2 itself on a 2008 R2 machine. Fair enough!
IT Pros across the world has started building their labs and even production network with 2008 R2 DCs and Exchange 2007 SP2, only to find out that things don’t work as explained in the SP2 release of Exchange 2007. Everything runs fine if you have atleast one 2003 SP1 domain controller in your network. You can have 2008 R2 DCs in the mix and Exchange 2007 SP2 will work fine.
But, things start to get messier when you only have 2008 R2 as DCs. Either you are building a new network with 2008 R2 as the only domain controllers or you are upgrading your 2008 servers to the R2 version. The following error is logged in the exchange setup log:
[ERROR] Cannot find at least one domain controller running Windows Server 2003 Service Pack 1 or later in domain ‘DC=DCName,DC=com,DC=DCName’. This could be the result of moving domain controller objects in Active Directory. Check that at least one domain controller running Windows Server 2003 Service Pack 1 or later is located in the ‘Domain Controllers’ organizational unit (OU) and rerun setup.
Microsoft has confirmed that it is a known issue with only 2008 R2 servers as domain controllers. Funnily enough, they say that when 2008 R2 BECOMES widely available, they will release a web update to solve the issue, after which Exchange 2007 SP2 will start supporting pure 2008 R2 domains. More info here
Call Microsoft Support if you have the issue in your production network. It looks like Microsoft Support is giving temporary fixes.
James-Lou, MSFT has more info in this thread
Root Cause: current ExBPA rule set excluding windows server 2008 R2 DCs/GCs, one of the prerequisite checks will fail as yours error info because it can’t find any windows server 2003 SP1 or windows server 2008 DCs
Affected ExBPA rules: Exbpa.pre-req.xml, Exbpa.readiness.xml
Resolution: We need new ExBPA xml files to replace the old under the path