My brother has a Powerbook G4 ver. 10.4.9 Processor 1GHz 1MB L3 Cache Memory 512 MB DDR SDRAM He no longer has the restore and install disk and we thought we might be able to upgrade to Leopard and give it to our parents to use - as I have my original disks. The computer isn't working so well. Sorry but I'm quite new to mac as I only bought mine back in March of this year. I know windows but not Mac. Can this be done? And if so how? Thanks!