So today I decided to go ahead and get a couple new hard drives, I got a Samsung 860 EVO 1TB and a WD Black 2tb, after connecting them to my computer I got the error "Reboot and Select proper Boot device". My computer has worked right before I turned it off to add the new drives. The drives I had before adding the new ones is a Samsung 960 EVO 250gb m.2 and a WD Blue 2tb. I have no idea what's causing the issue, I've checked the boot option in bios and its set to boot the M.2 which is the only drive with a OS on it. I tried removing the old drives and booting, didn't work. I tried only having the M.2 connected to boot no other hard drive and it wouldn't. The M.2 is connected straight to the motherboard so no cable that are lose.

Specs: Motherboard: Gigabyte z370 Gaming 3 CPU: I7-8700k GPU: pny oc2 1060 6gb RAM: 16gb Corsair vengeance 3000mhz