Windows 2000 server restore from backup

I recently had to restore a Windows 2000 server from my Backup Exec tape backup because of a HDD failure. All backup operations seemed to run fine but I can’t logon to the network from this 2000 server. The username and password I want to use for mydomain won’t work. I can logon to the 2000 server with the Administrator account for the local computer domain, but my network logon account for this machine fails. I also noticed that I have an “Account Unknown” in my user profile window on this server that is probably the one I need. I can ping my PDC which is an NT4.0 box, but I can’t seem to login to this server with the admin account for the domain. Is this a problem with the profile? Could it be an issue with the PDC? Please help!!