[CCleaner no longer working at all!!!]

Several day ago when using CCleaner it would run and scan my system, now it won't even do that. It starts like it's scanning then just stops. The latest upgrade that was installed is absolutely junk and screwed everything up and I can't get back to the previous version. This is what I get for actually purchasing the software! It actually worked when I still had the free version. 

[CCleaner stops or shuts down pc when trying to use]

Sytem specs HP Elite 8000 SFF running Windows 7 Ulitmate. When trying to scan system w/ CCleaner the program either stops working or will shut my computer off.