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I am unable to close Firefox, rebooting computer does not work, and an antivirus check has proved negative.

  • 4 replies
  • 3 have this problem
  • 3 views
  • Last reply by steveedw

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I have Firefox 29, and up until now it has been working perfectly. However, when I recently closed the program, and attempted to reopen Firefox nothing happened. I attempted to re-download version 29, but received the message 'Firefox is already running. Please close Firefox prior to launching the version you have just installed.' I also attempted to uninstall the program but received the message 'Firefox must be closed to proceed with the uninstall. Please close Firefox to continue'. I have rebooted the computer but I am still unable to close Firefox. I have scanned the whole computer with AVG anti-virus and no problems were revealed.

I have Firefox 29, and up until now it has been working perfectly. However, when I recently closed the program, and attempted to reopen Firefox nothing happened. I attempted to re-download version 29, but received the message 'Firefox is already running. Please close Firefox prior to launching the version you have just installed.' I also attempted to uninstall the program but received the message 'Firefox must be closed to proceed with the uninstall. Please close Firefox to continue'. I have rebooted the computer but I am still unable to close Firefox. I have scanned the whole computer with AVG anti-virus and no problems were revealed.

Chosen solution

Hello @streveedw

You can try to close the application manually from Windows Task manager.

  1. Right click your toolbar at the bottom of the screen and select "Open task manager"
  2. Go to "Processes"
  3. Sort Image names alphabetically by clicking it, and look for "firefox.exe".
  4. Select this process and click end process.

Now Firefox should be closed and you should be able to proceed with any other actions (like reinstall or uninstall).

I hope this helps.

-- Jørgen Juel

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Have you tried killing the firefox.exe process in the Task Manager?

  • Click Start > in the search box type taskmgr.exe
  • Go to the Processes Tab
  • End all firefox.exe processes.
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Chosen Solution

Hello @streveedw

You can try to close the application manually from Windows Task manager.

  1. Right click your toolbar at the bottom of the screen and select "Open task manager"
  2. Go to "Processes"
  3. Sort Image names alphabetically by clicking it, and look for "firefox.exe".
  4. Select this process and click end process.

Now Firefox should be closed and you should be able to proceed with any other actions (like reinstall or uninstall).

I hope this helps.

-- Jørgen Juel

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Problem solved. Many thanks for your kind assistance.

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Thanks for your assistance