Owner's Manual

Boot Menu
The Boot menu sets the sequence of the devices to be searched for the
operating system.
The bootable devices will be automatically detected during POST and shown
here, allowing you to set the sequence that the BIOS uses to look for a device
from which to load the OS. Below is a brief description of keyboard usage:
Key
Function
 , 
Selects (highlight) a boot device.
1 to 4
Loads the default boot sequence.
f, r x –/+ Shift + 1