This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox will not re-start without "ending process" with Windows Vista Task Manager.

  • 1 cavab
  • 13 have this problem
  • 22 views
  • Last reply by user633449

more options

Error Message: “Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.”

Have to start Task Manager and then end firefox.exe process.

Thanks all.

Error Message: “Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.” Have to start Task Manager and then end firefox.exe process. Thanks all.

All Replies (1)

more options

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

  1. Go to Firefox > Help > Troubleshooting Information.
  2. Click the "Reset Firefox" button.
  3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
  4. Firefox will open with all factory defaults applied.


Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!