We have two domain controllers running Windows Server 2003 that freeze up every day, and have to be powered off completely to bring them back up. Sometimes one of them freezes multiple times. We have been checking the event logs for clues, but haven't found anything helpful. We thought that the time service was the cause, and have set that to NoSync in the registry for now on one of the servers. We are currently in the middle of migrating from Novell to windows, so we have some buildings running Novell and Windows parallel. I'm not quite sure what other info you may need to better assist us with this.