I've made a note and will try and get that information in the guide. I'm kind of swamped right now so it may be a bit before a get to it. Different computer do this differently. Most newer computers will only show USB devices if they are connected when the computer boots. When USB booting first came out, most of the BIOS options existed to select the type of USB device (USB-CD, USB-ZIP, USB-HDD, etc.) and you could select them just like you select a CD/DVD or floppy drive. Now, most treat USB devices like internal hard drives; if they're not connected, they don't show up.