We have an AD Forest with two tree root domains. We will call them a.domain.com (Forest root domain) and b.domain.com. We have migrated all of the needed objects from b.domain.com to a.domain.com. Now I want to decommission b.domain.com. We have one DC left in b.domain.com. Do I just need to run dcpromo and check the box in the wizard that states " Delete The Domain Because This Server Is The Last Domain Controller In The Domain"?
When I have removed b.domain.com will the users that were migrated to a.domain.com retain their UPN? I.E.username@b.domain.com.
Thanks for any assistance you can provide!