With Ccleaner just make a backup of the registry first. And if some old backups have been there for months consider them ok to remove. I spent a couple months a year ago on a qwest to find the best registry cleaner and compared exactly what was found to be removed by each program. Each had minor advantages. IMO Ccleaner does the best average of all. Also in my experience you can safely delete everything that Ccleaner finds. I have honestly never had a problem. Remember you have a backup of the registry so you can restore to a non/less problem time.