Thanks for the reply and for your help.

I followed this instructions, and got the USB bootable.
But thought I must have some problem, as when booting it comes up with errors to the effect of:...

I don't mean to appear completely backward, but maybe it's unavoidable!?

I've downloaded the backtrack 4 ISO, and Unetbootin.

Extracted the ISO to a USB, no worries.
Directions instruct me to...