This is a pretty common question in the Avast forum. I guess ninety percent or more of the time "unable to scan..." does not represent a problem.
Sounds fairly hopeful.
I only have SUPERAntiSpyware, Avast (and Ad Aware)
The Avast screen will not expand/open. Takes up about 1/4 of the screen. Horizontal Scrolling and moving the column boundary, does not increase the Path statement.
One this drive, I have no restore. C D & E are is the first physical drive, and H and I are HP's recently re-installed main drive and back-up. I don't boot from that much...should, just to see it's going okay, but never get round to it.
The Avast setting was to 'do' C: only.
One thing I will do is to photograph the list and then run it again and see if it's in any way 'dynamic'. Just so odd that I can find not trace of it.
Mind you, since installing CCleaner, I can't find my cookies. I used to just go to them and pick out the ones I wanted, but now CCleaner seems to zap all or none.
I guess I'm expecting too much for freebies.