Novice booting from USB drive

I have ABR 10 Workstation with Universal Restore. I've finally been successful in creating a bootable USB drive with a 500GB external drive using GRUB4DOS. I've encountered a lot of problems recognizing different USB drives. Currently, I'm attempting to backup a hard drive where the USB hard drive is not being recognized. I'm confident that the rescue image I created does not contain the USB drivers needed.

I know I can create the rescue disk image and include the drivers but is there a way to load the drivers during the GRUB4DOS boot process or at the command line? I've also seen on the forum where it would be to my advantage to create a rescue disk image using BartPE and/or WinPE. I'm quite confused as to what these utilities actually do and I couldn't find any instructions that tell me how to install and use them from a NOVICE point of view.

Any help would be appreciated.

Thanks.

Kevin