We have a single server running as a file server / domain controller. We are having an issue migrating AD DS from Server 2003 to Server 2012.
When we run the Active Directory Services Configuration Wizard, we receive the following error at the prerequisites check:
Verification of prerequisite for Active Directory preparation failed. Unable to perform Exchange Schema conflict check for domain mydomain.local.
Exception: Access is denied.
Adprep could not retrieve data from the server server2003.mydomain.local through Windows Management Instrumentation (WMI).
I've verified that both servers Windows Firewall's are disabled, the Network Service has has logon right, and everyone has full permissions to WMI via WMIMGMT.MSC. I've also run commands to rebuild the WMI store and re-register.
We cannot connect to any PC via WMIMGMT.MSC on the LAN, so I'm starting to think its our Sonicwall TZ120. Everything else is working including DFS replication.