Doesn't see HDD in BIOS, what should I do?

Question

Hard disks

Information HDD is written and defined, but it is not in Boot, flash drives and Network are detected normally, it stopped detecting after changing Boot Mode from Legacy to UEFI
But if you switch back to Legacy, it sees everything

Answer 1

Well, that's right, it won't.
In order for a disk to be visible in Boot in UEFI mode, it must have a GPT partition structure and an additional partition with files for booting in UEFI mode, otherwise it will only be able to boot in Legacy. All this is done when installing the system, on an existing one you will have to sweat, biting off the partition and changing the MBR to GPT.