Use the original Lightning cable to connect your iPhone 8 to your Mac or Windows computer. Remove any other external devices from your computer's USB port to avoid generating a conflict. Close any open applications or programs on your computer to avoid any interruptions to iTunes during the restore process.
- When your iPhone is connected, immediately press and release the Volume Up, Volume Down, and then the Side/Power buttons until the phone reboots. Continue
- Hold the Side/Power button even when you see the Apple logo.
- Once you see the Connect to iTunes screen, release the Side/Power button. Your device has entered recovery mode, as indicated by this message.
- When you open iTunes, you should get a notification that says, 'There is an issue with the iPhone that necessitates it being updated or restored.'
- Choose Restore and then follow the onscreen instructions to complete the iOS restore procedure in recovery mode.
