NT4 Server falling apart in front my eyes

HELP!!!

I got a call on friday from a client, one of their users could log into the network ok but couldnt get any email. They run an NT4 server and Windows 2000 on the desktops (4 of).

True enough the user could see the network and everything on it but couldnt get onto the net or receive email. Checked the router, everything seemed ok there, nothing that would obviously block this client from getting to the net.

Replaced the router and hey presto the user could surf the net get email etc. But nobody could print. Lexmark networked printer that worked ok with the old router. Attached the printer to a local machine and shared it. The machine shows up when you go to load the printer on the other PC's but the printer attached to it doesnt.

In the meantime NT4 is throwing up "RPC too busy" errors left right and centre. Cant access the event viewer or anything of any note. And now the server is running like a dog with three legs and cramp.

Any ideas? Ive run spyware and virus scans on the server and on all PC's to rule that out and everything came back ok. Drives test ok what next?

I am stuck and were into day 2 of trying to get this resolved.

 

If you disconnect the server from the network does everything function normally on the server? We need to isolate the problems to the server or something external. Is the server the domain controller?