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Firefox cannot be installed or uninstalled as it is already running. Will not open

  • 3 Antworten
  • 3 haben dieses Problem
  • 2 Aufrufe
  • Letzte Antwort von cor-el

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I cannot get Firefox to run so I've tried turning on and off, uninstalling -- it won't let me as it says it is already running. I've tried a few of the suggestions in support, but none seem to work. Also some seem to be over my head and I'm worried to try them. I'm running Windows 7.

I cannot get Firefox to run so I've tried turning on and off, uninstalling -- it won't let me as it says it is already running. I've tried a few of the suggestions in support, but none seem to work. Also some seem to be over my head and I'm worried to try them. I'm running Windows 7.

Alle Antworten (3)

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Hmm, when I see that Firefox is already running message, I think that there's a ghost process running.

Go to your Task Manager by pressing the Windows start button, then typing Task Manager or you can press CTRL ALT DEL then go to Task Manager from there. Either way, go to Processes and end every Firefox.exe process that you see. Try to run it now.

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I have already tried that. It doesn't show any Firefox running at all on the Task Manager.

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You can check if there is a parent.lock file in the Firefox profile folder.


It is possible that your security software (firewall, anti-virus) blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access to internet for Firefox and the plugin-container process and the updater process.

See:


Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if this helps.