Hello, I am having issues with formatting my main drive in my Macbook Pro (mid 2009) to install Leopard. I have booted off of several Leopard and Snow Leopard install discs and attempted to use Disk Utility to format my drive. Everytime I try to format the drive I get one of two errors: 1. input/output error OR 2. Unable to allocate memory. I have tried using several hard drives. What the heck is going on here? Any help would be much appreciated.