I have a copy of Snow Leopard but the DVD drive on my iMac (3 years old, Intel) is kaput. I have a MBP which is fully working. Remote Install doesn't work as DVD sharing doesn't work for the installation although does for watching DVDs etc. I read about restoring the disc to an external HD and booting from that but on start up pressing and holding Option doesn't seem to work. I've tried with my keyboard (Apple) in different USB ports to no avail. How do I go about sorting all this out?