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.

Avatar for Username

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

This thread was archived. Please ask a new question if you need help.

Firefox thinks there's another instance running, but not true

  • 2 replies
  • 0 have this problem
  • 2 views
  • Last reply by pmbrown02

pmbrown02
pmbrown02
more options

I cannot use, update, uninstall, refresh, or reinstall Firefox (and haven't for four or more years). I always get this message: "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." But I have (obviously) shut down the computer entirely any number of times in all those years. What can I do? I will be taking college classes and Firefox is one of the few browsers that the college supports.

I cannot use, update, uninstall, refresh, or reinstall Firefox (and haven't for four or more years). I always get this message: "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." But I have (obviously) shut down the computer entirely any number of times in all those years. What can I do? I will be taking college classes and Firefox is one of the few browsers that the college supports.

Chosen solution

You can check this article.

Read this answer in context 👍 1

All Replies (2)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Chosen Solution

You can check this article.

pmbrown02
pmbrown02 Question owner
more options

Thank you so much. It was the parent.lock file. I was able to refresh Firefox. Just took a few moments.