Backup Mozilla Firefox preferences

In many of tips discussed on, you have to manually configure settings in Mozilla Firefox by typing about:config in the Firefox location bar and fiddling with the settings. In one of these kind of adventures you may mess your Firefox settings, so it is a better idea to backup your Firefox preferences. Here is how :

  1. Press the key combination Windows logo key + R to open the Run dialog.
  2. In the Run dialog, type %appdata%mozillafirefoxprofiles and press Enter.

  3. You will find a folder with its name ending in .default, for example plydapyi.default. Open this folder.
  4. You will find a file prefs.js. Copy this file to a safe location. This file contains the Firefox preferences for your default profile.

If later at any time you mess up your Firefox preferences (settings you can change from about:config page), just copy this file prefs.js to the same folder.