I have a powerbook g4 15" 1.5ghz which i just upgraded to 2gb of ram. I was wondering whether Leopard is compatible with my computer? It is currently running Tiger. Thanks! edit: i also bought a 160gb IDE hdd for my powerbook. should i send it to a apple store to get it installed or can i just send it to any independent store? also, is there any way i can save my old hdd just in case i need the data? like make it into an external hdd or something?