The machines are picky about the type size capacity and format type!
you want to get a 2 or 4 gigabyte usb thumb drive. And format it as FAT32.
also you need to ENABLE the software upgrade option!
I found this article on how to install software for you to review. If you're following these instructions and it's still not working I suggest calling into the support department at 1-800-821-2797.