Downgrading a Domain Controller in W2K Active Directory

gateguard used Ask the Experts™
When I run dcpromo to change a Domain Controller back to a simple server, are there any changes I must manually make to the Active Directory?
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No, as long as you have another DC in AD, it shouldn't, and I stress, SHOULD not be a problem.
Juliancrawford, on the other hand, gave some excellent information.
Good Luck...
In my MCSE class, i learned that this CAN be done but is NOT recomended.  As a test we all made our 2K servers a DC. then downgraded using dcpromo.  Our teacher stressed that it WILL work (we did not have to do anythign manually) but the machine will run "strange".  I have never done this, but i recommend formating.  That will be the "easiest" way to do it.
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kmorriss, so if we format the DC, how to remove it from Active Directory.  Just simply delete the object?  Somewhere I remember reading it must be "removed from the AD schema".


julian.  Those links contain a wealth of information.  the troubleshooting chart is great.  In our case, the networking and name resolution was ok.  The authentication was the problem.
sorry gateguard, i do not know about that.  If i remember correctly, we just ran DCPROMO and it did everything.  You should be save to format it after that.  I am sure there is a way to "unregister" a computer name from being a DC in AD. I am trying to remember.  we set up 5 domains in the class (all on different subnets) had one DC, then added one, then removed one.

I cant seem to find my Active Directory book, but i beleive you can select the server in the Domain Controllers section and remove one that way.  If it was running any services, you will need to move them to another domain controller (like DFS, if it was a Catalog server, etc..)

Hope this helps.
If you want to remove a DC, run dcpromo first.  The computer will not "run funny" unless something else is wrong.  DCPromo will ensure that the DC is removed properly from AD as well as remove the proper records from DNS that lists the computer as a domain controller.  Before doing anything, ensure that you are not running any FSMO roles on the dc.  If you are, transfer them to another dc before beginning.  Also, if the dc that you want to demote is a Global Catalog server, ensure that you make another DC a GC server before beginning the demotion process.

Thanks to ocon827679 for the information on the fismo roles. Having been running an AD SoHo network for a couple of years, and having reverted a couple of servers myself, I have never observed one acting "Funny" afterwards, and the only problem I have had was when I wiped a DC for a subdomain without, and I stress WITHOUT running DCPromo to remove it. I learned QUITE a bit about the command line tool NTDSutil, and I still have issues with the training domain showing up in browse lists. DO NOT just format the drive... 8-)


If dcpromo fails there are two questions:

1) how to restore the machine to a reuseability
2) how to get the DC out of the Active Directory

#1 is fairly simple

But #2 is what I'm unsure of.  Isn't there a tool for editing the Active Directory schema and removing pointers to the failed DC?
Use this to seize or transfer any roles:;en-us;255504&Product=win2000
This tells you how to get rid of orphaned domains:;en-us;229763&Product=win2000

There is also some very good information on removing lost or dead controllers in there.
If you simply go here:;EN-US;KBHOWTO
Select Windows2000, and do a search on NTDSutil, you will get some very good info on the tool, and it's uses.

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