I’ve just got the new free version of CCleaner and personally don’t feel as confident using it as the old version. On the old version there was a setting to ‘wipe free space’ with options of security levels. I can’t find this on the new CCleaner?
If you are having issues with CCleaner 7 then consider going back to v6.39: How to Roll Back from v7 to v6.39
Follow ALL of the instructions, particularly about turning off the Automatic Updating.