Not quite what I meant, but as I thought really. Go to the Apple menu (top left of the screen) and select 'About this Mac'. What's it say there about your processor and RAM? It's almost certain that your machine is unfortunately too old to play the file you're attempting here, due to the onward march of technology I'm afraid. That said - go on and post your specs here from that dialogue box, maybe there's another software solution I can think of
-Andiyar