You'd have to burn the downloaded ISO onto a CD/DVD (or another flash drive) and boot from the disc, then select the USB drive and try to boot from it. It worked perfectly well for me, so might be worth to go for it and see what happens.
You'd have to burn the downloaded ISO onto a CD/DVD (or another flash drive) and boot from the disc, then select the USB drive and try to boot from it. It worked perfectly well for me, so might be worth to go for it and see what happens.