Lots of red errors in the log - the first one (about the time of the original problem) is "Service Control Manager" "Event 7001" Then a few minutes later 2 for DCOM - 10005, followed by more 7001's. There's also a couple of 7026's and lots more 7001 & 10005's.
I cant run the checker unless I shut it down. Would it be best to try a re-start and wait, or do the check and see what it finds?
Thanks for the quick response, by the way.