First, I want to thank each of you who provided ideas that kept me looking.
Nukecad said what those of us who've been in the tech field very long were beginning to conclude... it's something simple.
So... I ran the install one again and looked at all the options, clicked the advanced button and when the destination window came up showing c:\Program Files\CCleaner, the "Next" button was grayed out.
Bingo! That meant that the folder was not only hidden, it was corrupted. I deleted it, reinstalled CCleaner and all is well.
I hope this helps someone somewhere.
Thanks again.