I think either something hasn't installed/uninstalled correctly and so is still trying to load from the registry
either that - or your registry is corrupt.....
what have/were you doing just before this started?
system crash?
this might be the only time I'll ever say this
try a system restore which may restore your registry.
Thanks, AC. No, there wasn't a system crash - and I can't remember what I was doing before the mesage first appeared. I do have a system restore and I might try that as you suggest. Derek