I'm in the process of trying to install Exchange 2010 Standard onto one of our servers, and I've hit a bit of a snag.
Two of the readiness checks fail, saying:
Coexistence between Exchange Server 2010 and Exchange Server versions older than Exchange Server 2007 SP2 in the same Active Directory Site is not supported.
The trouble is...we don't have Exchange 2007.
It does, however, seem that we had it at one time. The server didn't get used, and rather than uninstall Exchange, it appears that the server (a virtual machine at the time) was just done away with. Because of this, I can't go through the normal process of removing Exchange 2007 (or just upgrading it to SP2) to satisfy this condition.
I've followed directions that I found online to use ADSI Edit to remove all traces of Exchange-related objects from AD, but the readiness check is still failing. Is there something I'm missing? Something else that I need to do in order to remove Exchange objects from the schema so that I can install 2010?