Unable to re-add a 2003 domain controller after an OS reinstall

Posted on 2005-05-15
Last Modified: 2008-01-09
I had two Win 2003 domain controllers. Long story short, I recently had to reinstall the OS on one of them. Since I reinstalled the OS, whenever I try to re-add the server back to the domain, I receive an error stating that the domain controller already exists in Active Directory. Same results when I run dcpromo on it. I tried to delete it out of Active Directory so I could re-add it but I only receive the message stating that I need to run dcpromo to demote the domain controller before I can delete it. I obviously cannot run dcpromo on it to demote it since it isnt a domain controller anymore. I know I could just make up a new name for it but then I still have an extra domain controller in AD that doesnt exist.
Question by:einjester
    LVL 104

    Accepted Solution

    Take a look at this article on the NTFAQ. It outlined the process to remove a domain controller by hand. However if the server that you have rebuilt is already a member of the domain I would drop it out of the domain in to a workgroup. Wait at least 30 minutes for that change to replicate and delete the computer from ADUC.

    After making the changes, wait 30 minutes again for those changes to be deleted before attempting to add the server back in to the domain and then dcpromo it in.

    LVL 95

    Expert Comment

    by:Lee W, MVP

    Author Comment

    Actually I went straight to
    and ran the cleanup with ntdsutil as directed. Still was a no go at this point. Next, as the article suggested I went to and followed those directions all the way down to completing the instructions on cleanup from running adsiedit.msc. After that I was able to re-add my domain controller with complete success. This site rocks! Thanks a million!!

    Featured Post

    Looking for New Ways to Advertise?

    Engage with tech pros in our community with native advertising, as a Vendor Expert, and more.

    Join & Write a Comment

    Data center, now-a-days, is referred as the home of all the advanced technologies. In-fact, most of the businesses are now establishing their entire organizational structure around the IT capabilities.
    Join Greg Farro and Ethan Banks from Packet Pushers ( and Greg Ross from Paessler ( for a discussion about smart network …
    Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
    Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.

    731 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    19 Experts available now in Live!

    Get 1:1 Help Now