I don't know the details. But legacy boot mode support was supposed to be phased out between 2019 and 2021. Couldn't quickly find a good reference, here is at

I don't know the details. But legacy boot mode support was supposed to be phased out between 2019 and 2021. Couldn't quickly find a good reference, here is at least some: https://www.dell.com/support/kbdoc/fi-fi/000151899/no-boot-device-found-when-you-change-the-boot-sequence-to-legacy-mode?lang=en https://www.dell.com/support/kbdoc/fi-fi/000151899/no-boot-d... Edit: UEFI class 3 is the keyword https://en.m.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface https://en.m.wikipedia.org/wiki/Unified_Extensible_Firmware_...