I like both tools, CCleaner, and Glary Utilities, and I've never had any problem with either of them on any computer I owned.
Run CCleaner (it makes its own backup), use computer for couple of days. If everything is fine, run Glary.
I have to tell you this...When I bought my Vista (which, contrary to you, I like), I did a lot of cleaning to get rid of preinstalled crap, and obviously, I installed a set of my favorite programs.
When I was done, I had tons of registry leftovers, detected by CCleaner, and Glary.