We've had a child DC fail on us, and can't get into Windows on it as Directory Services is failing. A restore of the backed-up active directory hasn't worked due to a corruption, and so we've decided to demote the child DC and - for now - run AD from the PDC only.
dcpromo /demote doesn't work from Safe Mode or Directory Services Restore Mode.
We don't want to do a complete reinstall, as we have Exchange running on the child DC.
Anyone know how (if?) we can demote the DC within safe mode or otherwise get into windows?