Non Dell Hardware requires Secure Boot OFF. PCI-E M2 drives require F2 bios sata operation to be set to AHCI The samsung units also have their own NON NATIVE TO WINDOWS Driver.   Samsung_NVM_Express_Driver Samsung_NVMeDriver_InstallationGuide  
I have an Optiplex 7090 Micro with one M.2 (512gb) and want to add another M.2 (1TB) but I'm having a problem getting the PC to see the second M.2. I know the M.2 works and I'm sure I got it seated correctly but Disk Management does not see that it's present. The new M.2 is a Samsung 970EVO Plus NVmeM2. Any ideas as to what the problem might be? Thanks for you help.
Second M.2 SSD in a Optiplex 7090 Micro