and you set the 1st boot device in mobo bios to the usb key and disabled everything else? You also browsed to the dos file in the HP usb boot utility when you formated the usb key?
you can't burn the iso on a cd and boot from that or its usb key only?
try this one
http://h20000.www2.hp.com/bizsupport...reg_R1002_USEN