If you ever lose a DC or one gets deleted before it is properly demoted using DCpromo
… or maybe you tried DCpromo but it wasn’t able to clean up AD on your other DC’s.
As of Windows 2008r2, if you right click and delete a computer object that happens to be a domain controller you will be prompted with the message shown below. Just tick off the checkbox and away you go; now you don’t have to go into ADSI Edit and clean out the old server, ADUC does it for you!! 🙂
Don’t forget though… you still have to go into DNS and clean out all the Name Servers and other entries pointing to your old (now dead) DC.
Admittedly, I’m no AD expert…
Did I miss anything? Let me know in the comments.