To enter BOIS (basic input / output system) settings, follow these steps:
1. Using hotkeys while boot up
1.1. Turn on the computer and immediately and repeatedly press the hotkey (F2, DEL, F12, ESC, F10, Enter + F1, F3) according to your system.
After doing above steps you would be able to access BOIS.
Solution to Boot Device Missing or Boot Failed Error
To solve boot device missing or boot failed error, you need to get into BIOS of your pc / laptop. You can enter into it by pressing the hotkey during boot up. After entering BIOS, go to boot section and set boot mode to legacy support. Then save and exit to bios. The error get solved.