Well, if you have a Mac OS cd, try booting with that to recover your files. Then reinstall Mac OS, if you have the cd. Or, if you dont have the original cd, order a free cd from ubuntu.com so you can at least recover your files. Ubuntu is what i run on my computer, if you like it, install it. But before you do that, is your laptop a older PPC computer because the default cd for ubuntu will not work on a PPC.