Yep, registry cleaners are junk, nothing is any good, and WILL cause problems. Files won't open, file associations will be gone, conversions may error out, and a lot more, registry cleaners simply aren't useful, and do a lot more damage than good. I can't tell you how many times I've fixed computers in the last 18 years that were made almost completely by registry cleaners, including 'symantec systemworks' quite often, that was a total turd in every way, even the defrag sucked.

Reinstalling isn't needed either, just properly use your computer and don't install things that are not tested outside your machine, and you won't have problems. I have two android phones and test apps on one before moving to the other. Computers can easily run virtual machines, and should be used for anything even remotely questionable.