Installed M.2 now old boot drive isn't detected

[bibity74]

So I had my windows installed on a SATA SSD which worked fine but when I installed a new M.2 SSD my old SATA SSD is no longer detected in the bios.

 

[Emerald]

Have you tried a different SATA port?

M.2 shares resources with some of the SATA ports.