Something I’ve noticed in the on-line forums is that people are still advising others to use NTDSUTIL to perform a metadata cleanup to remove references to Domain Controllers that have been removed from AD without using DCPROMO (e.g. following a DC failure where demotion was not possible). Since Windows Server 2008 it has been possible to perform the metadata cleanup simpy by deleting the Domain Controller object using Active Directory Users and Computers.
A full explanation is provided here:
http://technet.microsoft.com/pt-pt/library/cc816907(v=ws.10).aspx