Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

When I try to start Firefox, I get a message that it is already running but not responding and I can't run another Firefox at the same time. I uninstalled and reinstalled. No change. Tried various other suggestions. Help!!

  • 10 پاسخ
  • 10 have this problem
  • 5 views
  • آخرین پاسخ توسّط cor-el

more options

When I try to start Firefox, I get a message that it is already running, but not responding and that I should close it before trying to run another Firefox. But I cannot find a way to close Firefox program that is not running as far as I can see. I tried uninstalling and reinstalling Firefox, but that did not work. I've tried various other things, but no luck. I thought programs should stop when the computer is turned off, but that didn't work either.

When I try to start Firefox, I get a message that it is already running, but not responding and that I should close it before trying to run another Firefox. But I cannot find a way to close Firefox program that is not running as far as I can see. I tried uninstalling and reinstalling Firefox, but that did not work. I've tried various other things, but no luck. I thought programs should stop when the computer is turned off, but that didn't work either.

All Replies (10)

more options

I followed the instructions to find a locked file. The Foxfire profile folder was empty. Is that the problem or what did I do wrong?

more options

To open your profile folder:

  1. See Finding your profile without opening Firefox on Windows 2000/XP.
  2. Delete the lock file.
more options

If the profile folder in missing or can't be located then create a new profile.

Create a new profile as a test to check if your current profile is causing the problems.

See Basic Troubleshooting: Make a new profile:

If that new profile works then you can transfer some files from the old profile (if that still exists) to that new profile, but be careful not to copy corrupted files.

See:

more options

When I tried to open the Profile Manager, I continue to get the message that Firefox is running but not responding. There must be something that I must be missing. Is there some command or file that is not working properly?

more options

How are you opening the Profile Manager?

Sounds that Firefox is still or already running.
See:

more options

Thank you. Thank you. Thank you. I tried the Kill Application first because I couldn't open the Profile Manager when I tried it earlier. But the Kill Application didn't work because there was no process listed that referred to "firefox". So, what the heck, I tried opening the Profile Manager using the address you gave me and the instructions for setting up a new profile worked. I am thrilled. Even though I lost all my bookmarks. Small price to pay, though. I can't thank you enough. Thanks for being so patient with me. Wahoooo!!!

more options

You're welcome.

Didn't you have an old profile?

Did you ever uninstall Firefox?
If you uninstall Firefox and remove personal data the all Firefox profiles are removed, so be careful with that check-box.


See also:

more options

Yes, I did uninstall Firefox. There was a "default" profile, but I'm afraid to touch it in case that was corrupted and caused my problem. I don't know enough about computers to even know whether that is possible. I am just so happy that Firefox works again that losing some data doesn't worry me, but I will try your suggestion for recovering data from an old profile. You've been great helping me fix my problem. Since you have credibility, what would you suggest for an antivirus program. I am currently using the 30-day trial of AVG. The time is almost up and I was planning on purchasing that product. What do you think?

more options

You can restore the bookmarks from the JSON backup in the bookmarkbackups folder in that old profile if you want to have them back.

For other data like names and passwords see: