[SOLVED] New m.2 drive not letting computer boot

[OnighteyesO]

I just installed a WD Blue 3D NAND 1TB PC SSD - SATA III and my PC stopped recognizing my old boot drive (Samsung 860 EVO 250GB)I don't see it anywhere in the bios, when I take out the M.2 it boots up just fine
MSI Z170a-G44
GTX 1080
I7-6700k
2 Samsung 860 EVO 250GB
I try searching online for an answer and couldn't find anything on it

 

[USAFRet]

Put the 860 boot drive on a different motherboard port.
Often, use of a drive in the m.2 port disables one or more of the other SATA III ports on the board.