|USB booting ought to be in the owners manual. Did you read it?|
In many cases usb devices can be in one of two places. One is under hard drives, so you'd have to move it up in the order from a cold boot to bios. The other is under some other usb device. Some usb's have been setup to act like a usb floppy, cdrom, zip or other usb storage.
"The era of big government is over," said Clinton 1996