SD
Thanks. A bit beyond my know how, I'm afraid. Anything else I should be doing to check out the pc?
The google advice was to go look for it in various places, but it would appear that in its early versions it did not disguise itself too well, (using phrases such as "man in the browser", but now, of course, it no longer makes itself visible.
I wish I'd followed the advice on this site some time ago about upnp and admin!!!