I guess because one pc isn't connected that would be the best choice. It's too bad they're not both desktops because you could just put the dvd burner in one and then in the other. I just thought of another thing: if you have an ethernet network cable (I know you don't have a network but pcs often come with network cables) you can just hook them up to each other, easy as that.
I'm sorry that I'm trying to help you as I keep coming up with more ideas, it must be annoying.