Possible solution for hanging after external disk migation

We had someone report that after migrating to an external drives, it would not boot. He resolved it by doing this:

I got the info from here:


I simply deleted the entire in MountedDevices and then the MountedDevices itself and all was good. Without this last step the system would hang.
So before cloning simply set the BootDriverFlags(as in the video) and delete MountedDevices.

We haven’t been able to test since we don’t have a system in that state, but if it works for you, let me know and I’ll add it to the setup doc.


I know this is an old post but this did help me after a day of not being able to boot into Windows 10 1903 on an external drive on a Mac after cloning. Note I did have to use a Linux dist. (specifically mint) on a VM on my Mac as macOS does not come with the chntpw utility.

This was the secret to get it working for me. Both BootDriverFlags and doing this got it to boot for me!