cantine

I got a new computer and installed the latest ccleaner64. For the most part it works. I use it all the time after I'm done using a browser. Randomly during the day when I try to open it up, it won't open. So I go into taskbar to try and kill it, but it won't. Just hangs there. I can't use firefox when this happens. I always have to reboot. What is the issue?? Windows 7 Home Asus pc