Hi.

Using Windows 10. Suddenly, Mozilla gives the "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window" message. I've tried all steps listed on the help site except reinstalling Windows 10, as the comment made said this would require reinstalling programs that did not come pre-installed on my PC, which I don't want to do if possible. I have uninstalled Mozilla, and the install stalls at about 70% with the aforementioned error message. Any help would be greatly appreciated! Thanks.