Remove active directory from this computer without updating forest metadata
In the event that the NTDS Settings object is not removed correctly you can use the utility to manually remove the NTDS Settings object.If you give the new domain controller the same name as the failed computer, then you need perform only the first procedure to clean up metadata, which removes the NTDS Settings object of the failed domain controller.If you will give the new domain controller a different name, then you need to perform all three procedures: clean up metadata, remove the failed server object from the site, and remove the computer object from the domain controllers container.
The Windows Server 2008 version of Active Directory Users and Computers (ADUC) introduced a convenient one click approach to performing metadata cleanup.command confirmed a replication error and showed DC00 as unavailable: Since a dcpromo was obviously out of the question, I used the Ntdsutil metadata cleanup command to effect the removal in the following steps. Entering ‘help’ shows all the options directly available : At the Ntdsutil prompt, select and type command again to verify and the result shows no replication errors.Start the Ntdsutil Tool: Open a command prompt as an administrator. I still had to go into the DNS forward lookup and reverse lookup zones to manually remove references to the offline domain controller object. As part of a successful demotion process, the Dcpromo wizard removes the configuration data for the domain controller from Active Directory, but as noted above, a failed Dcpromo attempt might leave these objects in place.The effects of leaving such remains inside the Active Directory may vary, but one thing is sure: Whenever you’ll try to re-install the server with the same computername and try to promote it to become a Domain Controller, you will fail because the Dcpromo process will still find the old object and therefore will refuse to re-create the objects for the new-old server.