Add a 'dd' prior to the first fdisk to cover situations where people are

Add a 'dd' prior to the first fdisk to cover situations where people are
uprading from very old or extended boot blocks which might not otherwise
be completely wiped by fdisk, boot0cfg, and disklabel.  Old left over cruft
often causes systems to panic with a BTX fault, usually due to bad
track/cylinder specifications in the boot sector which cause an overflow
(and often a divide by 0) fault in the BIOS.