I had already made all directories visible in Windows Explorer (that's the way I have it all the time), so it came as a real surprise when Avast popped up and said that Alasdair King was all over my PC. They must have seen the info somewhere. At that time, I had already deleted all references to him that I could see - the empty User directories.
I believe that the info I saw was a pop-up, more than likely to encourage me to buy some other package, but that pop-up must have been the result of some back-ground analysis. Of what, I have no idea, but Avast didn't suck "Alasdair King" out of thin air! I know that when a file is deleted, it is still there, but its directory link is broken so it can't be easily found. Recuva can find it, so is it possible that Avast picked up that information from the undeleted remnant, and fabricated the other directories...
Users\Alasdair King\Pictures
Users\Alasdair King\Documents
... and several others that I didn't note, so they could push a new product on me? I remember there was a button to resolve these issues, but I didn't push it - but if I had, would it have said "To resolve, pay us $$$"?
I have run another scan, but the same info did not result from the scan. I wish I had taken a screen-shot - but I didn't.
I also did a search of the entire C: drive for "Alasdair King", but it didn't find anything.
As I mentioned, I have recently moved from free Avast to a year's subscription, and my only reason for doing that was to stop the constant stream of adverts - but paying didn't work, so when the subscription ends, I'll go back to the free version. I only have a single PC - no phone - so I don't get a lot of advantage from a paid subscription - especially as it doesn't stop the advertising.