Firefox must close b4 clean cache

CCleaner for Windows
1

When running the latest version of CCleaner, a question box appears indicating that to clear the Firefox cache, Firefox must be closed. I exit Firefox before running CCleaner and Task Manager shows nothing running. How else to close Firefox for cleaner to clean Firefox cache?

After running CC, it notes that the Firefox cache has not been cleared.

What box have I not checked or unchecked? Running Firefox version 2.0.0.5

Thanks

2

Firefox will hang sometimes, if firefox.exe is not in the task manager. It would probably be best to reboot. It's not CCleaner, it's Firefox.

3
Firefox will hang sometimes, if firefox.exe is not in the task manager. It would probably be best to reboot. It's not CCleaner, it's Firefox.

Thanks, that did work. Believe I have problem with current installation of Firefox, although have re-installed most recent version. Agree CCleaner is working properly.