I went with the Windows 10 upgrade as soon as it was available for my Dell Latitude 10 Esentials tablet (2012 model), and by the time I decided I want to roll back to Windows 8.1, my 30-days had passed. So I created a bootable USB with the original Windows 8, but I cannot get the tablet to look at USB during boot up. USB is enabled, but I don't see how to select an order of boot so that I can tell BIOS to look at the USB port first.

How can I get this Latitude 10 Essentials to boot from USB?