Hello Fred: Finally success, Leopard is installed on my G4 PowerBook 867 Ghz. I traded out one of the Memory cards and replaced the original in the lower slot. Bingo, it started to load progressed past the time estimate a ways then said it cannot install, and try again, so I did, the second time it went sailing all the way. After a little use, the other 512 Ghz card will be tried again. This has been quite an experience, for me and I learned a few things, which includes your help and others also. I am a young 85 retiree and Your patience and help is greatly appreciated. It is nice that Mac People go the extra mile. Thank You and my best regards. John Sparks