Hi, sorry to hear Firefox has stopped working for you! Let's try to get it running again. Here are a few quick steps you can follow: 1. Restart your computer. Sometimes a fresh start can fix temporary glitches. 2. Try Firefox in Troubleshoot Mode. Open Firefox, click the menu (≡), go to Help, then select Troubleshoot Mode. This disables extensions and custom settings to help identify the issue. If Firefox doesn’t open at all, try launching it from a terminal (or Run dialog) with this command: firefox --safe-mode 3. Check for updates. If you can open Firefox, go to the menu > Help > About Firefox. It will check for and install any updates. 4. Clear the cache. Corrupted cache files can cause problems. Go to Settings > Privacy & Security > Cookies and Site Data > Clear Data. 5. Check for external conflicts. Recently installed antivirus, system updates, or graphics drivers could be causing issues. Try disabling any recent additions temporarily to see if it helps. 6. Reinstall Firefox. If none of the above work, uninstalling and reinstalling Firefox (without removing your profile) can often solve deeper issues. If you’re still having trouble, let us know what exactly happens when you try to open Firefox — do you see an error message, does it crash, or does nothing happen at all? And let us know what operating system you're using. I'm happy to help further!