Boot windows from USB4 m.2 NVMe SSD

Question

I am trying to boot Win11 from an external m.2 NVMe drive via USB4. I've tried many things from clean install to copy of an existing install. I can install Win11 to the drive, I can run Win11 installation from the drive, but but every time I go to boot Windows 11 itself, I get 'Boot Driver Error'.

The same drive and installation works fine on USB 3.1. BootDriverFlags in the registry is set to 0x10 as it should be. Have tried different m.2 NVMe drives with no success, and both drives work internally.

I suspect it is something to do with either:

• Windows not loading the External HDD driver. However, it works on USB3.1 - so this is unlikely.
• Windows not loading the USB4 drivers. This is possible - BootDriverFlags only has a setting to enable VHD (0x2), USB (0x4), SD (0x8) or USB 3.0 (0x10). How do I promote the USB4 driver to start at Boot?
• When plugged in as an external HDD via USB4 when already in Windows 11, Windows sees the SSD drive as an NVMe drive, not as an external drive. This may be to do with PCIe tunneling.

The same fault occurs whether I try this on a MiniPC or on my Surface Pro 9, which tells me it's Windows related.

Answer 1

After struggling with the same problem, it appears that the issue is with your UEFI not recognizing the drive as a USB drive. The USB 4 protocol uses pcie tunneling. The UEFI is likely seeing it as something other than USB or PCI mass storage. When the device is on USB 3, pcie tunneling is not used, thus the UEFI is able to see it as a bootable USB device. Without a bios update I don't see much likelihood that you'll get this working unless you're able to turn off pcie tunneling in your bios settings. I'm not sure how turning off pcie tunneling will affect the drive performance, as I don't have a setting in my bias to disable it. Hope this is of some use.

Answer 2

Hi Brian,

Sorry for the confusion. The installation proceeds just fine, the issue is when booting Windows from the SSD in the USB4 external enclosure I get the ‘Boot Driver Not Found’ error.

The same windows installation, SSD and enclosure, when plugged in via USB 3.1, will boot just fine.

Answer 3

Hello Ritero13

Welcome to the Microsoft Community!

Thank you for your feedback. I understand the problem you are having, when you try to install you get a boot driver error. I noticed that you are using an SSD as the installation media, and it is possible that a large capacity SSD may not be properly recognized by the system when used as the installation media, so this may be the cause of the problem.

So, I suggest you to use a small capacity USB flash drive (8G or 16G is the best choice) as the installation media and test if the problem still occurs.

Best regards

Brian - MSFT |Microsoft Community Support Specialist

Answer 4

Thank you for your further feedback.

I suspect that the problem you are currently experiencing may be related to USB 4.0 compatibility, and if you would like more information, I would recommend that you open the following website for more information.

https://www.usb.org/usb4

Disclaimer: Microsoft disclaims any implied or other warranties and/or guarantees and is not responsible for the information or any technical support you receive from third-party linked sites.

Best regards

Brian - MSFT |Microsoft Community Support Specialist