Cannot logon to W2K server

I have a W2K Server that gives the error message(The system cannot log you on due to the following error: The network request is not supported.) I have to reset the server for the error to go away. Also when I can logon, the event viewer logs are blank. The service is running and restarting it doesn’t help either. This server used to be a domain controller, but demoted more than a year ago. It has been working with no problems until a week ago. Any help would be greatly appreciated.