My computer refuses to boot from the USB even after I change everything that I can possibly think of on my motherboard's BIOS.
But I have booted from the USB twice in the past. The first time is when I first got the computer and needed to install a new operating system. The second time is when I installed Windows onto the whole hard drive and needed to reinstall Ubuntu.
It seems that it only refuses to boot if there is already an existing installation of Ubuntu on the hard drive.
Any ideas on what is going on?