Firefox starts automatically when I restart Windows
If you leave Firefox open when Windows shuts down, Firefox may automatically re-open with your previously opened tabs the next time you start Windows. Here's how to disable the feature.
Prevent Firefox from starting automatically
In the address bar, type about:config and press EnterReturn.
- The about:config "This might void your warranty!" warning page may appear. Click to continue to the about:config page.
- Search for toolkit.winRegisterApplicationRestart and double-click on it to set its value to false.
There's no need to restart Firefox; the changes take effect immediately.