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

Right after Instillation I get the Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window.

  • 1 tontu
  • 4 am na jafe-jafe bii
  • 8 views
  • i mujjee tontu mooy FredMcD

more options

I was getting the error of "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." And none of the solutions I found were working, including restarting my computer, closing background processes etc. So I decided that I would just uninstall firefox and reinstall it fresh. Only after the instillation when It started up for the first time I still got the same error message. How can there be firefox running when I've uninstalled the old fire fox / this is the first time I've opened the new install?

Please Advise.

I was getting the error of "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." And none of the solutions I found were working, including restarting my computer, closing background processes etc. So I decided that I would just uninstall firefox and reinstall it fresh. Only after the instillation when It started up for the first time I still got the same error message. How can there be firefox running when I've uninstalled the old fire fox / this is the first time I've opened the new install? Please Advise.

All Replies (1)

more options

Did you try this? https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding


Let’s do a full clean re-install; Download Firefox For All languages And Systems {web link} Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Mac: Open the "Applications" folder.
https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory.

Do Not remove the profiles folder.

Look for, and rename any Mozilla or Firefox program folders by adding .old to them. Do not rename the Mozilla Thunderbird folder.

After rebooting the computer, run a registry scanner. Then run the installer. If all goes well, remove the OLD folders when you are done.


If there is a problem, start your Computer in safe mode and try again.

Starting The Computer In Safe Mode;
Free Online Encyclopedia