Originally installed a subdomain to our domain. The DC had the wrong bit OS installed so reinstalled os without demoting dc.
Ran the how to remove orphaned domains from active directory and succeeded in removing the domain. I removed servers to a workgroup and the rejoined to the primary domain again.
Now I am trying to dcpromo back into subdomain but get the following error which kicks the server out of primary domain and into a workgroup.
Forest prep is not prepared for installing windows server 2003. Use adprep command line tool to prepare both the forest and the domain.
The version of the active directory schema of the source forest is not compatible with the version of active directory on this computer.