I have never had any problems with C Cleaner, but have had problems with other registry cleaners in the past. The only thing to remember with C Cleaner is before running it to save all your log ons in Options/Cookies in the program. It is self explanatory, and will save you logging on every visit to this place and other forums. One other thing is to agree to the back up option before deleting issues. This is purely a safety measure, and one that I have never had to fall back on. When installing either look for the lite version, or untick Google tool bar option.