I keep getting the panic kernel that says to restart, it wont' do anything else. I held shift down and it won't boot in safe mode. I ran a hardware test and got the following error: 4HDD/11/40000004: SATA(0,0) I'm assuming this means the hard drive has gone bad, is this correct? If so is there any benefit taking the thing to the apple store or should I just buy a replacement hard drive and use the disc that came with my mac (would this even fix the problem)? I have an '07 Macbook (black model) running Leopard. Any help would be greatly appreciated.