How Bootable Devices Work in UEFI Boot Mode

How bootable devices work in UEFI mode:

In order for BIOS to show a UEFI boot option for a fixed disk, there are only two possibilities:

• The fixed disk has this file EFI\boot\bootX64.efi stored in the root folder
• The OS installer has created a boot option on the disk.

Removable media is treated differently:

BIOS always builds a boot option for removable media regardless of media presence. The virtual media (virtual Floppy and Virtual CD) should show up in the UEFI boot menu as removable device boot options. If they do not show up, then they were disabled.