Firefox uses the user.js to make changes to browser functionality across updates; it overrides any changes made using about:config and does not exist by default.
See: http://kb.mozillazine.org/User.js_file
This is a template and should be used as such; I've included items that I think are important and often have to use another browser for banking or restart Firefox with everything disabled. Your mileage may vary.
An accurate way to find where to place the user.js is to type about:profiles in your URL bar. The profile in use will be listed under the heading:
This is the profile in use and it cannot be deleted.
Another option is to choose Help and then More Troubleshooting Information. About 9 lines down, you will find the Profile Directory information.
Using your favorite method, navigate to that directory and create your user.js file there.
- pyllyukko
- arkenfox
- Ryan Daniels' user.js
- Mozilla privacy tweaks from the Privacy Task Force
- Mozilla disable automatic connections, from Mozilla Foundation
- Spyware website
- Restore Privacy
