Thanks for replying - we've moved on a bit but still have an issue and are using a temporary server for now. However I would like to get to the root of the problem!
I have got the user account working again (I had another admin account as well)
What we have now is the server boots up to the Windows splash screen and then either goes no further - or takes a good 15 minutes to show the desktop (it was under 2 minutes before)
I have restored back with a Windows full backup, 1 day, 2 days, I have even gone back 1 week but still with the same result. The server is very slow and a lot of services don't start.
The strange part is that the password was changed 2 days ago (not the same time as the issue started) and whether I restore back 1 day or 7 days - it still accepts the latest password!
I have tried restoring to new hdd's and even a different server but still with the same issue.
OK I guess the backup is corrupt but the server was fine 1 week ago, so surely the backup should be ok for 1 week ago?
Issue appeared 4 days ago with timeouts in the log - only got to know about it 3 days ago when I couldn't logon. Not done a restore in a long time! (I know)