I've just done soemthing really dumb. A friend's laptop had been used on a domain for many years, and it was a company computer. He left the company and he now uses it as a home PC. He asked me to help him network it with his other home PC's yesterday, and I made a mistake.
I did not check that he had a local username and password set up. When I changed his network settings to move from a domain to a workgroup the reboot that followed left me with a login screen with no valid login, and I can't see how I can change settings to allow me to try and log on to the domain again.
I tried a repair installation of W2K, which went through everything, but it didn't prompt me for a new user name as I had hoped it would. ( I think XP does this, but W2k doesn't seem to).
I fear that the answer will be "bad luck, format and reload" but I am always an optimist.
Buckets of points for anyone who can help.