I recently purchased a imac g5 at yard sale, its got panther on it. I have been trying to update it to leopard. the dmg file is 8 gigs and the computer doesn't except dvd dl and panther doesn't except bootable usb drives. I tried to see if I could make a separate partition so I could boot it from there but the computer doesn't allow me to partition the internal hard drive because the original os boot image is on it. feeling frustrated please help