Driver finders and such can't find all known drivers or even the right ones. Registry cleaners, driver cleaners are also in that boat.

So yes, it can mess up a working system but "harm"? No. The hardware has yet to be harmed by such things.

ABOUT SYSTEM RESTORE. Too many causes from your antivirus choice to malware to registry cleaners to other.

It is not reliable enough for you to count on so you use the age old system of backup of what you can't lose.