[SOLVED] Can't Boot Windows From M.2 NVMe Drive

[Bert Rochau]

Hello,

I am attempting to do a clean install of Windows 10 onto an M2 NVMe SSD. I can successfully install Windows onto the drive, but I cannot actually boot into Windows after completing the installation.

• Mobo is a ASUS Z490-I
• M2 drive is a Corsair MP400
• The motherboard always identifies the M2 drive as a storage device
• The motherboard will only identify the M2 drive in the boot order if CSM is enabled
• When appearing in the boot order, I only see "Corsair MP400" listed; I do not see "UEFI MP400", "Windows Boot Manager MP400", etc.
• If I boot into the M2 drive with CSM enabled, I get a "Reboot and Select proper Boot device" message
• If I boot with CSM disabled, I go straight into the UEFI BIOS
• I have cleaned the M2 drive and reformatted it as GPT
• The M2 drive has an EFI partition
• If I disable CSM, I get a the following message: "Due to Microsoft Secure Boot regulations, ensure the Microsoft signed UEFI driver is contained in the plugged PCI-E based storages including M.2 SSD before set the Launch CSM to [Disabled]. Otherwise, the PCI-E based storages will be only available for the data drive usage. Contact the PCI-E storage vendor for the UEFI driver availability details."
• I have installed Windows 10 via USB drive onto the M2 drive (I know it's there because I can see the files there when I boot into Windows via a different drive)
• When installing and booting, I have disconnected all hard drives except the M2
• I have attempted to boot both with secure boot set to "Windows UEFI" and "Other OS" without success
• Fast boot is disabled

Any help in resolving this would be appreciated.

 

[SkyNetRising]

I might be wrong about this, but because it's M.2, doesn't it have to be installed in UEFI mode?

Not necessarily.
It's possible to install windows on nvme in UEFI mode as well as in legacy mode.