Hi Jack
CCleaner, itself, is generally OK.
It does have a registry cleaning option that we do not recommend.
If you have used this then it could be the cause of your problem.
Try a System Restore to a date just prior to your problem.
In Win8 this is not quite so straight forward as previous operating systems,
click here
Open the Search Box and type in ......system ...... "System Recovery Options" will be at the bottom.
Your files / photos / data will be fine.