I have a 2005 PowerBook G4 15" 1.67GHz 1GB currently running Tiger 10.4.11 Im trying to upgrade to Leapord 10.5 from an Image file. I have looked at loads of guides online, but im struggling to get it to reconize my external HDD as a boot device. I have made a backup of the image file on my external HDD and when i restart holding option button, it only finds the mac HDD. Any one know what im doing wrong or know of any guides that I can follow? Am I better trying to boot form a USB stik or burning a Dual Layer DVD? Or should my external HDD work ok?