Thanks for the tip, hazelnut. I am adding this reply in case it might benefit another user in the future. Examining my machine, I found 3 recycle bins: one on C and one on each of 2 external USB drives, one of which is configured RAID-1. The recycle bin on the RAID drive showed "empty" when mousing over the icon, but in Drive Properties, it showed 1 folder, 3 files, 103GB of content. Since my original CCleaner issue involved "over-reporting" of 104GB that could be saved, I guessed that the RAID recycle bin was the culprit. I reviewed your post re: use of the "RD /S /Q C:\$Recycle.bin" command and ran it successfully on C drive and one external drive, but the RAID drive returned a notification that the RD command could not be executed, because it was "not allowed by storage policies. Contact your administrator." Administrator is me, and I could not figure out a way around storage policy issue. Actually, I admit I never really understood it, so I looked for a workaround. I was preparing to move about 600GB of content off the RAID drive to other storage, so I could format the drive and cure the problem, I hoped. Before doing that, however, I decided to try connecting the RAID drive to another laptop to try the RD command from a machine that might have different storage policies. Did so, and it worked!! Issue resolved.
As to CCleaner, this was informative, because I did not previously realize that the program monitors recycle bins on all of my attached storage drives. A nice additional benefit.
Thanks again,
Another happy customer!