We've been testing Windows 7 for deployment in our domain and have been having random and sporadic problems with this error. Randomly a user will attempt to login to their computer and after a long wait they will receive this error. Clicking OK they will then have to sit for an extended time, 2 to 20 minutes, with the "Logging off" message, which will return them to the log-in screen. Most times they can immediately re-key in their password and they will logon normally with no intervention. There are no events logged to the event logs, and there does not seem to be any pattern to the user, computers, time of day, or any of the other usual suspects.