Seems as though a lot of people have this problem, but I can't quite figure out the solution. I installed a M.2 SSD and changed the boot order in the BIOS to move it up, but the system still seems to try to boot from the HDD every other time it starts up. I will get an error message saying it can't start, I'll shut it down, and then it will start up fine with the SSD the second time. I've reformatted the HDD. I was hoping I could just leave the HDD in there and use it for storage but it seems like it needs to be removed or the bios needs to be updated or something.