Question Trying to set up Dual Boot - Computer boots Win10 disk from USB adapter but not from SATA or PCIe - - is this a mobo issue ?


Dec 26, 2014
The Short Version: I want to dual boot windows 7 and windows 10 on one machine, originally built for win7. I can boot win7 normally off SATA 3 SSD, and I can boot the windows 10 off of its M2 disk when plugged into a M2 to USB3 adapter, but when I try to boot it off of an internal location, it does not appear in boot devices in my mobo. It does appear as a usable, accessible disk in Windows 7, however.

I have an older computer, built November 2014, running Windows 7x64 on a Gigabyte GA-Z97X-UD3H motherboard. I run Win7 off of a SATA III Samsung Evo 512GB SSD. The mobo BIOS version is version 7, last I checked.

I have another computer which I used to use for work, a laptop running Windows 10x64 off of a 1TB NVMe M2 drive. That laptop had similar specs to my desktop, and my hope is to move this M2 drive into my desktop, and to dual boot win7 and win10. I prefer win7, which is why I am "still" using it, but I recognize that some software I want to run will stop working on win7 soon, and so having an alternate (and maybe a slow transition into using win10 on the system) is my goal.

Here is what I have tried, and the result:

1. tried installing win10 drive into M2 slot on my motherboard.
Result: Not detected by motherboard, not detected from windows 7, cannot access.

2. bought sabrent NVMe M2 to PCI-E adapter and installed win10 drive into spare PCI-E x8 slot.
Result: Does not appear in boot devices, but does appear in windows 7, and can be accessed and files have RWX access.

3. bought sabrent M2 to USB 3.0 adapter, put win10 disk into adapter and connected to PC
Result: drive detected by BIOS and booted into repair mode, ran fix on boot procedure for the disk, it now boots on the machine via USB adapter. Needs new drivers for the hardware but otherwise appears functional.

4. cloned M2 drive to internal SATA 3 SSD (samsung evo, but a new one, not the Win7 disk) with hope that I could instead boot from this drive.
Result: Can access with RWX privileges from Win7, but does not appear as valid boot device in BIOS.

I am unsure of what to try next. The M2 drive is detected as a valid boot device only when it is plugged into a USB 3 port via my adapter. It also appears as a "UEFI Device", where in the other installation methods it either does not appear at all, or it only appears as a nondescript device, and will not boot.

My guess would be that there is some settings change that needs to be made in order to make the mobo harmoniously support booting both win7 and win10. I don't really know anything about windows boot requirements after 7, because I have not built or installed windows on a machine for myself since this build in 2014, and I never had to deal with windows 8/8.1/10/11 before. I do know that the USB adapter works despite the other M2 adapters not working. I just don't know why they would not be detected, given that at the very least, the M2 to PCI-E adapter let me see and access the disk in windows 7.

I am hoping someone can help me figure out why my machine does not recognize my win10 disk unless it is plugged in via USB port. My hope is to either use the M2 to PCI-E adapter and boot from that, or to clone the M2 drive to a SATA 3 SSD and use that instead. If anyone can help me to accomplish either of these two goals, then I would be very grateful. Thank you for reading, and please ask me if there are any ambiguities.

EDIT: I forgot to mention, I also called gigabyte, and their very helpful customer service representative told me that, from their perspective, they felt the problem may very well be with the M2 to PCI-E adapter, and that I should try other hardware or even cloning the drive to a different device, before I choose to update my BIOS. They did indicate a safe BIOS (version 9 IIRC, sorry I have the notes "somewhere" in my messy office space :) but advised it was not a good idea to try unless nothing else worked. This is why I tried step 4 above.


Oh, on moving OS to another machine, you have to do a 'Sysprep Generalize' (look it up), on the old machine, after backups. Then shutdown and never boot from again until in the second machine. You'd have to reinstall drivers, of course, but you get to keep Programs and all other settings.