Windows Update for Byte 3

I have a Byte 3 that is currently running Windows 10 1909 version. I would like to upgrade it to the latest 20H2 version but there is insufficient space on the built in 32MB drive to do the update. I tried running the update and using an external USB drive. It is a SanDisk Ultra 64GB drive. The upgrade seemed to proceed OK and got to the point where it said it would need to restart multiple times, I clicked OK and I was logged off while the update was supposed to be installed. Unfortunately after the first reboot there was a message on the screen asking me to insert the removable media (which was already inserted) and to press OK. The only option was to unplug the USB drive and reinsert it and press OK but then the update process informed me that the update had failed because of a boot error and reverted back to 1909.

Now here's the issue. The PC is at a relative's house 3,000 miles away and I manage it using AnyDesk. The person at the other end is not computer literate so there is a limit I can ask of them.

I found out about the message regarding plugging in the external media by having them take a photo of the screen and sending it to me. I had her then unplug the USB drive and reinserting it.

I seem to remember hearing somewhere that some brands of USB drives cannot be used as external media for OS upgrades but I can't remember any details. Does anyone know of a brand of USB drive that will make an unattended upgrade complete successfully?

Thanks

Mike