A colleague removed a PC from our NT domain by changing the network config to use a workgroup. Now we cannot log on to the machine at all, because the only two local machine accounts, Administrator and Guest, are disabled. It appears the only account used on the machine was a domain account, which can no longer log in. What can I do from here?
I've seen this happen one too many times that it's almost regular procedure to have a copy of offline NT password and registry editor lying around.
It will let you re-enable accounts, change passwords, pretty much everything you need to get back into the system without reformatting.
It's best to standardize a local admin username/password across machines in the domain so when you need to service them you can do so easily, and without network access. This is especially useful for virus infected machines which you don't want on the network while you perform a scan.