Can't Boot from Samsung 960 EVO M.2 Drive, Sort Of

installed W10 on the above drive. When I try to boot from it, it doesn't work. It says insert boot media. I had already installed W10 on the drive. And I can see the drive in BIOS and windows explorer when booting from another drive.

Oddly, when I boot from an SSD drive also connected, that works, but it asks if I want to use W10 on Volume 4 or 7. When I choose 4, the Samsung M.2 drive does indeed boot.

Anyone know what is going on? Obviously I want to boot from the M.2 without needing another boot drive.

Thanks.

CPU - i7 6700K
Board - Z170A M3 Gaming
RAM - G.SKILL TridentZ Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM
OS - Windows 10 Pro
GPU - none
Sound Card - None

swarfega said:

Make sure to change the boot order in BIOS so that the 960 is listed first.

did that. and also unplugged the SSD, leaving just the M.2 doesn't work.

The problem is that the OP installed Windows onto the second SSD while the first SSD was still connected. Instead of putting separate boot files on the second SSD, it set up dual booting off the first SSD.

feeling dumb. looks like I didn't disconnect all other drives when installing. Never had that problem before. Anyway, thanks much.

All you have to do is shrink the OS partition by 100 MB, create an EFI System partition, and use the bcdboot command to put the boot files on it.