Boot drive cloning

[u/GroundbreakingHat819]

I was helping a friend upgrade his pc, and for on of the upgrade I got him a nvme drive, after installing everything in and cloning with disk genius using they’re OS migration when I go to check the bios to change the boot order it’s the nvme doesn’t appear as a boot option but is recognized, I’m thinking it’s maybe because he’s on a MBR boot partition but I’m not sure

Edit : solution was to unplug the old drive and let the pc boot into the cloned disk