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.
