force closing programs

I've been using ccleaner for a while now without any problems. but a couple of weeks ago I was cleaning my PC and ccleaner asked if I wanted to force close Firefox. I was using it at that moment so I pressed no. From then on ccleaner stopped asking me if I want to force close it anymore and just skips it, so I have to manually close it through the task manager, while that isn't a huge problem, it is mildly infuriating. (I also did not check the do not show this message again box, so I don't know why it stopped asking in the first place)

is there a way to make ccleaner force close the program again?

You can try Options>Advanced>Restore Default Settings to see if that will clear it and start asking you again.

The only way I've done similar in the past, after ticking the 'Do not show again' then wanting it back, has beeen to uninstall/reinstall CCleaner.

(At that time there wasn't a 'Restore Default Settings' button available).

However just closing Firefox normally is enough to allow CCleaner to clean it without skipping.

You shouldn't need to use Task Manager. Firefox does not normaiiy run in the background once closed.