I think what you need is to re-flash the chip with the correct bios...there's no problem if your HDD is locked because by default it's really locked to your xbox. Your main concern now is to make your modchip work, if neither banks with the flashbios are not working then you need a programmer or a hotswap to make it work. But first, you should state here if what happened with your install, were you able to access the flashbios before messing up with flashing the bios? YOu need to provide more info...