Windows 2000 'SystemAdmin' error?

[AceT]

Hi.

For some reason I have just started to get a 'SystemAdmin' error appear in W2K when I try to copy files.

I Am logged in as an administrator and now, whenever I copy a file/directory and then try to paste it anywhere, I get the following error message -

Fatal Error
Unable to create an instance of required object: ServerAdmin

Explorer then quits out and the desktop 'reboots' - in other words it reappears wuth half of the taskbar icons missing.

Any ideas on how to fix this?

Thanks.