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Restore Firefox about:config Defaults Settings

Firefox about:config is a feature which lists application settings (known as preferences) that are read from the profile files prefs.js and user.js, and the default application. If you have messed up your Firefox about:config settings and would like to know if there is a way to reset it back to the default settings. Sure there is. Here’s how you can do it.

Method 1 : Reset All Settings to Default

1. Open Firefox and type about:config in the address bar. Enter.
2. If there is a warning appear, just click the button to confirm.
3. On the screen about:config, look at the far left icon on the tab.
4. Click it and choose Restore Defaults

Method 2 : Reset an Preference

1. Open Firefox and type about:config in the address bar. Enter.
2. If there is a warning appear, just click the button to confirm.
3. On the screen about:config, context-click (right-click) on the preference and select Reset.
   Note : If you added the entry via about:config, the preference will no longer be listed after restarting the program.

Method 3

1. If Firefox is running, close down Firefox completely.
2. Start Firefox in the Safe Mode. For that, click Start, open the All Programs list, and navigate to the Mozilla Firefox folder.
3. In the Mozilla Firefox folder, select Mozilla Firefox (Safe Mode).
4. You can also start Firefox in Safe Mode by clicking Start, selecting Run (or use the Start Search box in Windows Vista) and then entering the following in the text field:

   firefox -safe-mode
   

5. Firefox should start up with the following Firefox Safe Mode dialog.

   

6. To actually reset your about:config to default, in the above dialog, select the option: Reset all user preferences to Firefox defaults.
7. Click on the Make Changes and Restart button. This will cause all changes you made to the about:config to be overwritten by the default values.

Now that your about:config is reset, you can start fiddling with it again!!