Article ID: 318698
When you try to delete an orphaned NTDS Settings from Active Directory Sites and Services, you may receive the following error message:
Note that only one NTDS Settings ordinarily exists under each server in the Servers folder in Active Directory Sites and Services. If two NTDS Settings are shown, the one that does not have connection objects associated with it (in the right pane) is probably the orphaned NTDS Settings.
DSA object cannot be deleted.
The Dcpromo.exe demotion process must delete NTDS Settings from a server. However, the Dcpromo.exe process may not delete NTDS Settings even if connection objects are deleted. If you have multiple domain controllers, the Active Directory replication process may not delete NTDS Settings from this domain controller.
To work around this problem, complete the following procedure on a domain controller that has an orphaned NTDS Settings:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.