could you please give more details??? For example, do you mean Firefox when you say mozilla???? If so, have you tried to reinstall Firefox??? I will get back to help you but More info please

Hi GuitarFan, I assume Firefox previously worked normally for you...

Can you associate the problem with any recent change to Firefox (such an update or new add-on), or Windows, or other software on your system?

If you look in the Windows Task Manager, do you see firefox.exe starting to run?

To launch the Task Manager, press Ctrl+Shift+Esc. Then click the Processes tab. You may want to click the Image Name column heading to alphabetize the list. Then look for firefox.exe, which would indicate that it started loading but perhaps is stalled. Is it there?

By the way, if you haven't shut down and restarted Windows since this problem began, you might want to try that.