I would steer clear of these type of paid for type programs.. They may well be flagging up problems that don't exist; to make you part with your cash!
I do use C Cleaner - You can get a free download from
here
It generally clears out most of the accumulated rubbish and also can check for any registry problems. You should back-up the registry before allowing it to delete the problems. The back-up routine is offered at the time.