Unlike most previous computers, This new one has a backward BIOS command structure. It used to be that you went into BIOS to turn on or off onboard or added cards. That no longer shows up as such so it's missed by many (I've worked with computers and BIOS since the 8086 days).
1. Do a reboot.
2. As soon as you see the first indication of activity press the F2 button repeatedly every 2 or 3 seconds until the BIOS screen comes up.
3. Move over to the BOOT tab.
4. Move down to "Secure BOOT Control"
5. Press Enter to allow change
6. Select "Disable"
7. Exit with save.
The reason for this change to Enable "Secure BOOT Control" within the Windows 8 OS was to assure prevention of attached devices from accessing the system before security had been activated at OS start. Unfortunately, this allow the system to prevent access to the added graphics card (sound, firewire, etc.) but it also creates a conflict in BIOS. Nice idea, but overkill.