M.2 not booting

[MrSycyS]

Hello!

 

Low to midrange level of knowledge...I hope so. I will be googling almost everything you say tbh.
Bought an ADATA XPG 8200 1TB a while back. Used it as a storage while my SSD was main drive. Everything was fine, it worked well.
Now had time to install W10 in M.2 .... and then it all started.

First of all it didn't show up as an option where to install Windows, no matter the boot order, no matter which drives were connected, no matter formatting, swapping between GPT or MBR didn't help. Until it did? 

So it eventually showed up as an option (don't know what changed) and I installed OS, it restarted couple of times and then I proceeded with software installation.
After I restarted PC it showed "reboot and select proper boot device" even tho boot device order is fine. My M.2 showed in it and I tried to swap it with UEFI (that default option in BIOS). Nothing changed. Changed Bios settings to defaults and Bios was up to date last I checked. No errors from SFC or DISM.

 

Now I installed W10 in my SSD to have a workstation and my M.2 shows up in My Computer list...I'm able to use it as a regular storage device, but simply cannot boot from it.

CPU: AMD Ryzen 1600X
MB: AsRock Pro4 AB350
GPU: MSI 1080 Aero
RAM: Corsair Vengeance 2400mhz ddr4 2x8GB
M.2: ADATA XPG SX8200 1TB
SSD: ADATA SU650 480GB
HDD: Seagate Barracuda 2TB

I've gone through all first page of google and I'm all out of ideas, since BIOS part is definitely not my strong side.

I feel bad already that everything is always not working for me, so please be patient with me.

[Levent]

That drive is notorious for failures.

 

[MrSycyS]

Now that I've installed W10 in SSD it has letter "C" assigned to it
I had the same letter assigned to M.2 when I installed windows in it. 
Can this situation make a conflict in future? Does it matter?

[MrSycyS]

11 minutes ago, Levent said:

That drive is notorious for failures.

 

I hope my problems are a result of my lack of knowledge...

[Levent]

2 minutes ago, MrSycyS said:

I hope my problems are a result of my lack of knowledge...

I dont think so. No drive should just disappear, this sounds like typical issues SX8200 users experience.

[MrSycyS]

1 minute ago, Levent said:

I dont think so. No drive should just disappear, this sounds like typical issues SX8200 users experience.

Well it now shows up in BIOS and is recognized in Windows by other drives... let me at least hope for a boot solution.. XD

[MrSycyS]

Update!

Posted problem in my local FB forum. 
A guy got in touch with me who had the same problem. 
Basically I installed OS while I had my HDD connected. Correct me if I'm (or he is) wrong but OS can get partially installed in HDD and that cause the said problem. I didn't see that as a factor for a error as I could find the correct partition where to put OS and presumed PC would too.
So...I reinstalled OS when everything but the M.2 was disconnected. Reconnected everything afterwards and now it does boot from M.2...for now at least. I will update if this fails.