I have a secondary hard drive in my computer which I use for mostly games and a few photos. My main drive is an SSD which I boot from and have a few programs installed on. I just bought a new 2TB drive to replace the secondary drive and have copied all of my files over. Now that I have removed the original secondary drive whenever I turn on the system I am met with "select a proper boot device." I've checked the bios and the SSD is still at the top of the boot order so I don't know why it won't let the computer boot as the other drive was nothing more than a companion drive. As soon as I plug the original secondary drive back in the system boots as normal but windows is definitely installed on the SSD. The hard drive only has games and photos.