Toshiba Satellite pro C850 wont boot from usb and it wont let me enter the bios settings to change the boot settings

[bennettsfencing]

Toshiba Satellite pro C850 wont boot from usb and it wont let me enter the bios settings to change the boot settings

 

[hang-the-9]

Why won't it let you enter the BIOS settings? What happens when you try? Does the keyboard not work? Did you make sure your USB drive is actually functioning as a boot drive in another system?