Where's my desktop background?

[bentwing60]

Dropped off my 4 yr. old Toshiba Satellite 550A at a local, well regarded smaller electronics store for a problem I had had no luck solving. Their tech didn't either and said I should by a new computer and took my money! So I took it home and hit the forums again and somehow it got fixed. The problem is, He had installed CCleaner and run it, (freeware) and not deleted it so I used it after the mystery fix and was amazed at how well it did.  So, after a couple of months I ran it again and my desktop background disappeared as a result. Icons but only a black desktop, and I know about r-click personalize and have several times. It's above my pay grade, anybody out there with a clue?