For more information, see the article Switch to Firefox Extended Support Release (ESR) for personal use. Firefox ESR does not come with the latest features but it does have the latest security and stability fixes. Firefox Extended Support Release (ESR) is an official version of Firefox developed for large organizations, such as universities and businesses, but it can also be used for personal computers. Install Firefox Extended Support Release. Instead of downgrading to an older, insecure version of Firefox and changing your update settings, you should consider these alternatives: In the General panel, go to the Firefox Updates section. Click the menu button and select Settings.
Click the menu button and select Options Preferences. In the Menu bar at the top of the screen, click Firefox and select Preferences.
To prevent Firefox from automatically updating itself after you install an older version, you'll need to change your Firefox update settings: Important: By default, Firefox is set for automatic updates.
