I think I'm having a similar problem when I use Outlook Exploer and Word. When I run CCleaner (the latest version), it changes some of the editing options! I found that if I left Windows "open" (but minimized), CCleaner no longer changed its settings.
I also went to the CCleaner "Tutorial" and discovered something that I'd overlooked all these years: on the left-hand side of the screen, there are two tabs -- one of them is "Applications" where you'll find all your installed programs listed. I just un-checked Microsoft "Office" and now I can run CCleaner with impunity! Tah-dah!
Karl K.
McKinney, TX