Restore the Default Settings in Firefox Without Uninstalling It

Have you found yourself wishing that you could start fresh with Firefox but the thought of uninstalling and then reinstalling it makes you cringe? Well now you can get that fresh clean Firefox goodness back with a simple process using “Safe Mode”.

For our example, here are some pre-reset screenshots.

The main browser window.


The add-ons window (note that add-on compatibility checking is disabled).


The about:config settings window (with one of the custom added about:config settings displayed).


Note: This will leave all of the extensions and themes you have installed intact (returned to their original default preference settings) and does not remove them. Removal of extensions and themes will still have to be done manually using the add-ons window.

Resetting Your Installation of Firefox

There are two ways that you can start Firefox in “Safe Mode” in order to do a reset.

The first way is to access “Safe Mode” through your Start Menu in the Programs area.


The second way is to access “Safe Mode” using the “Run” function which can also be found in the Start Menu. Enter “firefox -safe-mode” (without the quote marks) in the blank and click “OK”.


Once you have started Firefox in “Safe Mode”, you will see the following window. Here you will be able to choose the actions that you would like to perform.


  • Disable all add-ons – all extensions and themes will be turned off while in safe mode
  • Reset toolbars and controls – removes any changes or customisation that you have made to the toolbar(s)
  • Reset bookmarks to Firefox defaults – removes your current set of bookmarks and resets to the original default set of bookmarks
  • Reset all user preferences to Firefox defaults – restores the options, preference settings, and the theme back to the original default settings (Note: This will also reset all the entries in about:config back to their original default settings and remove any custom entries that you have added.)
  • Restore default search engines – restores all of the original default search engines (based on the language version you have installed) without removing any of the search engines that you may have installed/added

For our example, all but the first option will be selected. Once selected, click “Make Changes and Restart”.


Once Firefox has been restarted, you can see the difference in appearance (including the original homepage).


The extensions and themes are still installed and functional (notice that compatibility checking is no longer disabled as in the screenshot above).


The original search engines have been restored (the previously added Google-cliKball engine is still there).


The bookmarks are back to the original set.


A quick check for the custom about:config setting displayed above shows that the about:config settings have all been reset to default.



If you have been having problems with your installation of Firefox and are considering a clean reinstall, this could prove to be a much simpler (and quicker!) alternative to get you back up and running again. 

Note: Depending on your History retention settings (i.e. retain for 30 days) before resetting Firefox, you will find that your browser’s history for that period has remained intact (very nice!).

Akemi Iwaya is a devoted Mozilla Firefox user who enjoys working with multiple browsers and occasionally dabbling with Linux. She also loves reading fantasy and sci-fi stories as well as playing "old school" role-playing games. You can visit her on Twitter and .