My MSI Z97 motherboard (updated to the latest bios) seems to regard all of my bootable devices - SSD, HD, DVD-RW, flash drives - as legacy only. Specifically, if I switch to "Windows 8/8.1/10 mode ...

Why Convert Legacy BIOS to UEFI? Converting Legacy BIOS to UEFI can significantly enhance your system's performance and security, particularly if you are planning to upgrade to the latest versions ...

How to convert MBR hard drive partitions to GPT To determine if you have UEFI on your PC you will have to access the system software of your particular motherboard.