deletes things that you're still using
have subscribed for 1 month to test and get rid of broken registry entries. it cleaned that up but also broke a whole bunch of other applications, such as windows notepad and my browser firefox. had to reinstall them.
unfortunately, pc cleaner appearently also does an automatic clean every few days. it started an automatic clean 3 days after purchase / installation, which killed my browser and notepad again. i can imagine there are more broken programs on my pc now... and i even went in to tell it manually what to clean up and what to keep, but the options are rather vague "bullet points".
this is the reason why i uninstalled and canceled my subscription. pc cleaner is like an overzealous cleaning lady: if your stuff doesn't look important enough, it's going in the trash.