It may be because the startup setting was accidentally removed or reset. To fix this, you can add Firefox back to the startup folder manually. Press Windows + R, type shell:startup, and press Enter. Then, copy the Firefox shortcut from your desktop and paste it into the Startup folder. You can also check Firefox’s settings by opening the browser, going to the menu > Settings > General, and making sure the movie option to start Firefox automatically when your computer starts is enabled. Additionally, open Task Manager (Ctrl + Shift + Esc), go to the “Startup” tab, and make sure Firefox is enabled there.
