USB Windows 10 “inaccessible booting device” error

I upgraded my internal hard drive which contained windows 10 pro, I wanted to keep the old drive as an external USB booting drive (connected through SATA USB adaptor ), now when I try to boot from it, I see the windows logo and after a few seconds it gives me the error "inaccessible booting device" .

Given that, The drive works fine as an internal drive. As USB drive I am able to boot to the safe mode.

Do I need to change anything in the setup (maybe in the registry) to make it USB bootable as well?

Thanks in advance.

Solution 1:

set this value in the registry HKLM/SYSTEM/HardwareConfig/{..guid..}/BootDriverFlags = 0x14

I'm pretty sure this is all tools like FlashBoot and WinToUSB are doing