Question M2 NVME drive will no longer boot my windows 10

Apr 26, 2021
So recently I was making some hardware adjustments and additions.... Previously I was running a single M2 NVME 250Gb Samsung EVO plus with my windows 10 and then a 500gb Samsung SSD through SATA. That all worked fine.

Then I decided to add an extra nvme drive (1tb) to the mix and of course stuff started going haywire with the PCIe lanes being to full so my SSD got pushed off and then I would reload and then one of the nvme drives would be pushed of... Needless to say I was scratching my head thinking what in the world is going on here....
This is of course before I read about the problems with PCIe lanes reprioritizing differently depending on your Mobo.
So now for some reason, whatever I do, I can't get my windows 10 to boot from my original nvme drive.
So I wanted to know if the windows nvme got wiped out or something from me messing around with stuff so I installed ubuntu 20.04 via a USB stick onto the newer drive so I could look to see if all files on the older nvme drive got erased or something....
Low and behold, all the windows files seem to be there still when I check via the ubuntu desktop file system.

I think maybe I messed up the bootloader in the windows file system on the original drive but I'm not sure.... Ultimately I'm just stuck now wondering if this is fixable or am I stuck with a non bootable Windows on that drive and thus I will need to salvage what I can via transfering most of my person files onto the newer nvme...

I hope I've made this clear enough to understand. Please ask more questions if need be.
Thanks folks.


Apr 7, 2019
I would salvage what you can first from the M.2 NVMe Drive before doing anything else. Backup all the data you need to a safe place (external hard drive).

Firstly let's start off with how many lanes your chipset has.
How many devices you can connect to your motherboard depends on how many PCI-E lanes your motherboard chipset has.

For instance the X570 chipset (from AMD) can support 2x M.2 NVMe Drives, which is what you were trying to achieve. It has a total of 36x PCI-E Lanes
So 16x PCI-E Lanes for your GPU
M.2 Drives need 4x PCI-E lanes each.

So you're left with (36-16-8 = 12 PCI-E Lanes) with a X570 chipset motherboard from AMD
The remaining 12x PCI-E lanes are for the other PCI-E cards, USB ports, sound, network controller (See here)
This makes going towards a X570 chipset motherboard a reasonable upgrade if you are using a B550 AMD motherboard which only has 20x PCI-E Lanes

Delving further down, there are some configuration nuances that each motherboard model will do if you connect certain devices (i.e. some devices will run at half the PCI-e lanes or the PCI-E slot will cease to function if you connect certain devices, etc.), which you can see from your motherboard's manual.

As long as the drive is still functioning, then you could give it another shot after you back up the data and decide to reformat and reinstall Windows on it again.
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