That was one of the first things I did. I'm sure it is enabled. I'm almost positive it has to be my computer and not what I'm doing because as I said, it worked fine on my friends computer with me doing the exact same steps.
I also just updated by BIOS, thinking that could help, but I'm still getting the same error message and the 'Boot error' if I try to boot.
I read one tutorial, linked here:
USB BackTrack Linux install via Windows | USB Pen Drive Linux
That mentions the error I'm getting (as well as a picture) but it says to just click continue through it, which I do, but it doesn't seem to work in my case.