This can happen for two main reasons, and this page explains what these are and provides two solutions.
1. CCleaner finds more Registry issues after you run a clean:
If you run the Registry Cleaner, find some issues, and fix them, CCleaner can find more entries when you click Scan for Issues again. This is nothing to worry about.
How to fix this problem:
Run the Registry Cleaner a second time to remove these extra Registry entries. If this doesn't work, please read our next point.
2. Your operating system locked the Registry entry you want to clean:
If you run the Registry Cleaner and can't clean the same Registry entry after a second attempt, this is probably the cause. In this case, you should leave it alone.
How to fix this problem:
You can't stop your operating system from locking this entry, but you can hide it from future results by adding it to the Exclude list. See the screenshot below for reference.
To do this, side-click the entry and select Add to Exclude list.
Once done, you won't see this Registry entry again when you click Scan for Issues and view the results or view the cleaning results.
