I have a user that is unable to open Firefox. When she tries, she gets a popup that says Firefox is already running, but is not responding. I have followed the troubleshooting guide, but I am still having this same issue. I uninstalled, and reinstalled Firefox twice with fresh downloads from the Mozilla website. We are still having the same issue. Unless I close Firefox through task manager, the window will keep popping up.

Any assistance will be greatly appreciated.