When I put the SSD in my old computer (Win10) and rearranged the drives I ended up with the drive order out of place as far as what the BIOS looks for. I typically turn it on, it doesn't boot up, I turn it off with the switch, and turn it on right away and it boots, because it remembers now where the SSD is. I've tried rearranging and that didn't work. There is a lot of stuff crammed into that machine so reaching the SATA plugs on the motherboard is difficult.