How-To Geek

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 .

  • Published 06/15/09

Comments (14)

  1. Alex Leonard

    I’m quite fond of running “firefox.exe -ProfileManager”. Within the Profile Manager I have a completely blank profile which I can start up to test things etc, and most recently I migrated to a brand new profile as the old one was feeling incredibly sluggish.

    I think my old profile has been on the go for about 4 years and I figured that it was most likely carrying a lot of old baggage with it.

    So in setting up the new profile I used Xmarks to carry all my bookmarks and passwords across. Then reinstalled the necessary plugins. My places.sqlite went from 235mb to 2.7mb or something, and the overall profile folder has gone from 376mb to 43.5mb.

    The only thing lost in the process was my history, but I’m quite happy to start afresh with that.

  2. Richard Iurilli

    Nice tip.

    Do you have a loist of all the extensions installed before the reset? I’m curious as to what a few of those buttons are.

  3. Paul Eck

    An easier, albeit dirtier, option is to simply delete your profile folder. Firefox will automagically build a new one for you. It is normally located in ~/.mozilla/firefox under Linux (specifically Ubuntu). Windows is a bit trickier. In XP you will find it in C:\Documents and Settings\username\Application Data\Mozilla/Firefox or C:\Documents and Settings\username\Local\Application Data\Mozilla/Firefox. In Vista it is in a similar folder except it’s C:\Users\username\Local\Application Data\Mozilla/Firefox or C:\Users\username\Application Data\Mozilla/Firefox . The Windows locations are from what I remember and are not verified. The folder you want to delete will probably be named xxxxxx.default where xxxxxx is a bunch of seemingly random letters and numbers.

  4. Asian Angel

    @Richard Iurilli – Here is a list of the extensions that have buttons showing (all extensions listed from the pre-reset screenshot and by area).

    Upper Left Corner: Delicious Bookmarks and WOT

    Upper Right Corner: The 1st and 3rd buttons to the right of the address bar are from the Toolbar Buttons Extension, the 2nd button is from the Cache Viewer Extension, followed by Forecast Fox

    Lower Left Corner: Measure It

    Lower Right Corner: Ad-Block Plus, Delicious Bookmarks (displaying again in the status bar), Dictionary Switcher, Firebug, Orange Dictionary (Thai-English), and Stylish

  5. Kurt

    Thanks, but this tip didn’t work for my problem. Using system restore has removed the ability to “restore defaults” under Firefox search engines–the option is greyed out. This is a “bug” that Mozilla acknowledges in their Mozillazine help forums, although they don’t see it as a bug. I do. (What is a bug if not incompatibility with features of the OS?) After my last system restore, it removed Google as my default search plugin. Running in safe mode didn’t fix the problem. (Obviously, reinstalling Firefox, including earlier versions of the same, didn’t fix the problem either.)

  6. mac1681

    Thank you to Alex Leonard. Did you first save setting to a flash drive? I don’t know what I’m doing, but like Linux/Mozilla/Firefox which a good-guy-geek installed for me and then updated last year with a newer version.

    My main question:
    Will loading all this stuff onto a flash drive save the things I want; allow me to get rid of the stuff I don’t; and leave alone the things I know nothing about?
    Please respond in common terms. I am not a practised computer person. Thanks,

  7. TweetDeckTV

    Holy crap. All you have to do to restore default settings is open your Task Manager, click the Process tab, click on the Firefox.exe in the left column, and click End Process. Firefox has a unibrow. Someone needs to pluck it.

  8. Jim

    Well you see I made the search bar and the tools at the top go away. So now there is nothing to right click on to put them back.. I tried reinstalling but it saved it D: please help me

  9. Mike


    do you know a plugin or setting for firefox where I can save current settings and restore the settings whenever I want? Sometimes some crazy software installs plugins, toolbars or changes my search engine without asking and then I am pissed…. for example ICQ, it changes everything and it is a hell of work to get back my previous settings…


  10. Asian Angel

    @Mike – You might take a look at this. ^__^ While it is an external program it does do a wonderful job of preserving your setup.

    Backup Your Mozilla-Based Software with MozBackup

  11. Asian Angel

    @Jim – All that you need to do to start getting everything back is press the “Alt Key” on your keyboard. Once the Menu Toolbar reappears right click on it to “select and get” your other toolbars back. ^__^

  12. rt

    you forgot to say to close firefox if it is already opened. the safe-mode only works if it is closed. if not is just opens it like normal.

  13. Tien Trinh

    Thank you very much. Very nice.

  14. Kuby

    Thank you for the great tip. I was able to restore me firefox back to the originial settings. Also, I found your website via bing, your article was the first entry. Nice work!

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