I bootcamped Windows on my MacBook, but it was partitioned wrong, now my Mac OS, which was Leopard, is gone. Is it possible for me to just upgrade now to Snow Leopard? Or will I have to find my Startup disc for leopard to start it up? When I get this screen, all I get is one hard disk with "Windows" under it. Will it be possible just to buy snow leopard and just go from there?