When I run the best pratices analyzer on exchange 2010 I get this error. Domain has an unknown Exchange signature It says the Current DomainPrep version is 12639 which seems correct for 2010 technet says to re run the prep? http://technet.microsoft.com/en-us/library/aa997081(EXCHG.80).aspx to prepare.. http://technet.microsoft.com/en-us/library/bb125224.aspx My question is.... Is it safe to RERUN these setup preps AFTER exchange is installed and running? setup /PrepareSchema setup /PrepareAD setup /PrepareDomain

Did you downloaded the latest ExBpa updates?

There were none... it trys to update each time it runs.

I dont see any reason to re-run the setup commands. ExBpa has had issues in the past when it didnt recognize the schema signature. I would ignore it.

Hi, Based on my research, I found that this is a known issue and it is fixed in Exchange 2010 Service Pack 1. Please upgrade to Service Pack 1 and run ExBPA again. Thanks.Novak Wu-MSFT