NT Service Database Lock

I am fighting with a nasty high end NT 4.0 WS used for video editing. The problem is with RAS & TCP/IP protocol. They do not work – no messages, just unresponsive. When trying to remove RAS & TCP/IP, I get the error message that the Service Database is locked, then the machine locks. Any suggestions on how to get around this? I do not know a lot of the history, but the user had contacted the system builder’s tech support and they had them delete several files (unknown at this point), install sp6a and attempt to use the ERD (it was never updated…) but according to the user, this just made more problems.