If you ever found yourself sitting in front of a dead Hackintosh system (for example another operating system’s boot loader invaded it’s Master Boot Record (MBR) like Linux’s GRUB, and keeps telling like: Error 13: Invalid or unsupported executable format.), and would like to use it in it’s original way, follow the steps below:

1) get yourself a 10.4.8 bootable (Intel) DVD

2) boot from it and press F8, and type -s to enter single user mode

3)  type:
fdisk -e /dev/rdisk0
flag 2
update
write
quit
reboot