Somewhat tough to explain but here goes. We have had this issue on approximately 15 of our Windows 2000 servers at random times over the last year. Most recently on a "Powered by Windows" NAS server. I'm not sure exactly what the cause is, but there are a repeating 1000 and 1001 events. Also, when you look at the local group memberships on the server itself, all "domain groups" that are members of the "local groups" show as a GUID and do not appear to be functional. Removing TCP/IP and reinstalling it localy fixes the issue but I need to know the cause. I have read all the tech docs I can find on Event 1000 and 1001 but they don't seem to apply in our case. Group policy not getting applied seems to be a side affect of the main issue. I can log on to the domain and use network resources with no problem. It has occurred on servers with various SP's and hardware config. Anyone have any ideas on this???