Windows 10, 32 GB eMMC laptop: `Windows can't be installed on drive 0 partition 1.`

I bought a new Dell Inspiron that has a 32GB eMMC disk but wanted a clean install from a Microsoft Windows 10 ISO (not the Dell image).

I duly booted off a USB key with the latest ISO off MSDN and wiped all the partitions. When I recreated a partition and try to install Windows on it I get this error:

Windows can't be installed on drive 0 partition 1.

Clicking for details...

Windows cannot be installed to this disk. This computer's hardware may not support booting to this disk. Ensure that the disk's controller is enabled in the computer's BIOS menu

I tried enabling legacy mode in BIOS, UEFI again and using diskpart to toggle between GPT and MBR in various combinations - all to no avail.

The problem was I had built the bootable Windows USB using the wrong option in Rufus.

I was reusing a USB Key I built a while ago but am reasonably certain it was built with

MBR partition scheme for BIOS or UEFI computers

When I rebuilt the USB key using

GPT partition scheme for UEFI computer

Windows Setup was able install to the eMMC disk.