Fix the error “Firefox is already running but is not responding”

errorFirefox keeps your complete personal settings, bookmarks and other information to Firefox profile. However to launch this, Firefox requires an unlocked profile and if it is not then it displays “Firefox is already running but is not responding” error message. However you can know about how to avoid such error message which consists of how to end Firefox processes, initialize the connection to file share, Remove profile lock file, Check access rights and how to recover the data from locked profile.

End Firefox processes

When Firefox does not survive normally before you have used it last, after that it may be that Firefox may still run at the background but it is not seen. Now you can shutdown and then restart your computer so that you can see the problem is still there or it has gone. Now instead of shutting down the computer, you can also use Task manager to exist Firefox process.

The steps that you can use are mentioned below:

  • You can hit on Ctrl + Shift + ESC or can right hit on empty spot in windows task manager and then select Task manager to open it.
  • When the task manager is opened, hit on processes tab


  • Then select firefox.exe from the processes list and then hit on ‘end processes
  • Click on Yes in task manager warning which appears
  • However to end the other firefox.exe processes, you should repeat the above mentioned steps.
  • At last launch the Firefox normally

Eliminate profile lock file

After shutting down your system or while restarting your computer, if it does not help you then Firefox may be existed without removing the lock file. However to remove the files, just follow the below mentioned steps:

  • Restart the computer but don’t start Firefox
  • Then go to Firefox profile folder and hit on ‘start’ and after that on ‘run’


  • Type “%APPDATA%\Mozilla\Firefox\Profiles\” and after that hit “OK


  • After that new window tab will open consisting of profile folders
  • Then open the folder with ‘default in the name to open it’
  • After that delete the parent lock

Note: Well if you get error message “cannot delete parent: The file or directory is corrupted and unreadable” while deleting parent lock file then restart your system and after that for errors, just check the hard drive.

Initialize connection to file share

When the profile is stored on file share, just try to access the file share before you use windows explorer

Check access rights

Firefox has the full power to create files in profile folder. This type of situation happens when you try to use file system which is mounted with read-only.

If you want to check the profile folder then you have to follow the proper access right:

  • Open Firefox profile folder
  • After that go up one folder
  • Just hit on right profile folder and select properties
  • Then go to general tab and make sure that read-only is not ticked marked

Restore data from locked profile

If by chance you are not able to unlock the profile by following the above mentioned steps, then you should use profile manager so that you can create a new profile and then move your data from the locked profile to new one.

  • First open Firefox profile folder
  • Hit on the help menu and then choose troubleshooting information. After doing all this, troubleshoot information window will open
  • Now from the application basics category, hit on shadow folder and a new window with your profile file will open
  • Now at the top of Firefox window, hit on file menu and then select exit
  • Just hit right button on a folder or the file you want to copy
  • At last open your new profile folder and after that right click inside the folder and select paste