Information
This setting dictates whether the Firefox Update service will notify the user when update related events occur, such as updates being available or downloaded. It is recommended that updated-related notifications be displayed.
Ensuring users are aware of update-related events may reduce the amount of time Firefox remains unpatched.
Solution
Perform the following procedure:
* Open the mozilla.cfg file in the installation directory with a text editor
* Add the following lines to mozilla.cfg:
lockPref("app.update.silent", false);