I just got a new Macbook (I it) and I want to put Leopard on my other two macs. One is a Powerbook G4 12" which I tried to install Leapord on. I put in the DVD, rebooted, it went to the gray boot screen, a blue screen, then a black screen with the pinwheel cursor. The DVD drive was doing something since it made a lot of noise, but the installer never started. Is this because the included discs are locked to the specific computer, or because the PB is too old or something. Additionally, will these discs work to upgrade to Leapord on my G5 tower. That's way more important than the Powerbook, but I'm a little worried to start messing with it if the install won't be successful. Sorry if this has been answered before; I am no good at forum search.