Intel m.2 760P not showing up in Bios

[synthie]

Hi,
I have Windows 10 running on an old hard drive and just got a new 512GB Intel SSD 760P M.2.

After installing it on my ASUS mobo I can see it in Win10. Great, so I used a Win10 installation USB stick, installed Win10 on the Intel SSD (with a few going forwards and backs, now using GPT instead of MBR).
After Win 10 was installed, the machine rebooted and put me straight into the installer again where I can install over the just installed OS... I'm going in a loop, not good.

Manually rebooting and checking in the BIOS it looks like the M.2 SSD is not recognised at all so I can't boot from it. In the BIOS I used UEFI, CSM is enabled. I tried a couple of permutations but nothing works to show it in the BIOS.

I also disconnected the other HDs I have in the system with only the SSD remaining, restarted, which puts me straight into the BIOS with no possibility to boot.
Connecting the old hard drives again I boot into my (old) Win10 environment and can see the SSD there without a problem and see that the Windows system folders are there.

I read up on various forums but am at the end of my knowledge, can anyone give me an idea what else I could try?

Thanks for your help in advance!

 

[synthie]

I'll answer my own question, the problem is solved. It was an out of date Bios in the Asus motherboard. I have the Asus Z97-K, version 2308 did NOT support the M.2 SSD. The later version 29xx something worked and the SSD showed up in the BIOS and booted from it. Hope that helps someone else.