Dear Ed,
As usual, Indy has a very good suggestion, namely checking how AC points to the server, by name or by IP. If your other domain computers are working because they were set up to use an IP to point to the AC server, then your problem has a simple fix and everything that I suggested would be a huge waste of time.
***
Just to clarify, I doubt that you have a virus problem.
Tweaking.exe and combofix.exe are not primarily anti-virus programs. They're registry-repair programs that like to be run with any anti-virus program like AVG disabled to avoid interference.
For example, tweaking.exe can trigger anti-virus warnings when it cleans up file permission and ownership problems.
Cheers,
Carl Fogel
