I've yet to use CCleaner on W10. I'd not use it until you read what others are finding and certainly not it's registry cleaner.
You might be looking at using W10's refresh feature.
I have taken all USBs and all else including the Graphic card and connected graphics to the m/b.So it is a simple PC.
It worked fine after reinstall, I loaded my OpenOffice and was downloading Ccleaner. It loaded and worked but its download would not stop, I switched the PC off for the night.
Next morning I switched it on and found it still downloading, though the Cclearer worked ok.
Then suddenly PC turned off. I switched it on and found a strange situation: PC switches on and off every second, it goes on and on.
Is there a way to stop it other than switching off from the mains ?