Hi, Rusty!
It is typical that this problem arose after my daughter had gone home!
We have a "home -grown" computer expert on the premises for several hours......and the problem arises after she leaves!
Yes, I did unplug it at the wall - that is always my first reaction to any problem!
Our anti virus protection automatically does regular scans, so I doubt there is a bug.
YB does tend to go around switching on/off everything in sight!
Despite his being steered away many times!
Maybe he touched something he shouldn't?
(He switched off the TV socket.... no one noticed ...and "Eggheads" didn't record!)
Anyway, fortunately the computer seems to be fine again now!
So fingers crossed it stays that way!
I shall now take a (very) belated look at the crossword!