How to fix firefox is already running but not responding ?

This error occurs when Firefox is closed but is still running in the background. Firefox is either in the process of closing or is frozen and hasn’t quit properly. In rare situations, there may be a problem with your profile.

Steps to fix this issue :

Wait a Few Seconds :

If you’ve just closed all your Firefox windows and quickly tried to open a new one, you may see this message. This is because Firefox is still running in the background, doing housekeeping tasks and saving your data before quitting completely. If you wait a few seconds and try launching Firefox again, you may find that it opens properly.

End Firefox.exe in the Task Manager :

If waiting a few seconds didn’t help, then Firefox has failed to quit properly. While all Firefox windows may be closed, Firefox itself is still running in the background. It may be frozen and using no system resources or it may be chewing up your available CPU time.

Luckily, ending Firefox in the Task Manager is simple. First, open the Task Manager by pressing Ctrl+Shift+Escape. You can also right-click your taskbar and select Task Manager.

Firefox won’t appear in the list of running applications because this list only shows applications with open windows. No problem – just click the Processes tab.

Type the letter f and you should instantly jump to the firefox.exe process. You can also click the Image Name header to sort the process list alphabetically and locate firefox.exe.

Once you’ve located firefox.exe, select it and click the End Process button.

This is what the message means when it asks you to “close the existing Firefox process.”

Restart Your Computer :

Restarting your computer is the nuclear option and, quite frankly, isn’t a very good idea. If you encounter this error, you can always fix it without restarting your computer.

The “restart your computer” suggestion is for less-experienced users that may not want to deal with the Task Manager – restarting your computer works because it ends all the processes on your computer, including firefox.exe.

Call  +1-856-514-8666 for more help and support to  fix firefox is already running but not responding.