Asus UEFI/BIOS options - How to boot from DVD?

I just bought a new PC and the default installed OS is Windows 8. I want to install Windows 7 but when I go into the boot options screen I only have one option:

Windows Boot Manager

I can't find my DVD drive. It is plugged in and visible under SATA options. How is it that I don't see it in the boot options menu?

The weirdest thing is that the drive is working perfectly inside Windows. So Windows 8 can detect it but the BIOS can't? I'm stuck with Windows 8... Any ideas?

Solution 1:

To get the DVD drive to show up in the boot menu, you might need to go into the BIOS (actually (U)EFI Settings) and enable Legacy (BIOS) Mode or the UEFI Compatibility Support Module (CSM) or similarly worded option:

(Screenshot of Asus Zenbook Prime UX31A-DH51 BIOS with CSM disabled.)

(Screenshot of Asus K55A BIOS with CSM enabled.)

Note: You might also have to disable both Boot / Fast Boot and Security / Secure Boot Control.

Solution 2:

See my answer to THIS post. Try to change the UEFI boot options by "restarting" Windows8 while holding down the shift key, to enter advanced reboot menu.