So i am a weee bit behind times and i am still running Leopard (10.5.8). Recently my brother purchased a MPB 13" (which is what i have) and he has Snow Leopard on it. Am i able to use the disks that came with his mac and load them into mine? Or do i have to go out and purchase Snow Leopard. I simply asking this before just trying because i'd have to go crazy looking for the disks and i'd rather know the answer before i go crazy. Thanks.