Since the files get permanently deleted when you click on Run Cleaner in the Cleaner tab, shouldn't there be an option to back them up in case something goes wrong? :-o That way if your system starts acting weird after using CCleaner, you can always restore everything (both Cleaner and Registry deleted files) to find out if it was really caused by CCleaner or just a coincidence.
Also, it would be nice if the back-up filename didn't depend on the time of back-up. I had to wait another minute before I could proceed to the next item in the list. (I like to run the Registry fixer separately for each item so I know exactly what I'm deleting.) I once manually changed the filename number at the end so it wouldn't overwrite the previous back-up and didn't notice until too late that the back-up saved as a File and not a Registry Back-up. I couldn't restore it later on when I experienced problems with HP Total Care which had never given me any problems in the past. Now there will always be the doubt in my mind that maybe CCleaner deleted a crucial element of my HP help and support program. If I had been able to restore everything that CCleaner deleted from my system, then the doubt would have been erased (if the program still didn't work after restoring everything to its original state).