I have a late 2007 macbook pro 3,1 (15.4-inch: 2.2GHz) I can't afford to go out and buy a new computer so I want to upgrade my old computer but have never done anything like this before. I want to upgrade the ram to 4 8 or 16 GB. How do I know which hardware to buy that will match my computer model. Do I need to upgrade my OS from Leopard in order for the computer to recognize the new ram (I heard that could be an issue) I would also like to upgrade my hard drive to free up space. Is this possible? if so what hardware is best suited? If I do these upgrades can I upgrade my Operating system to Mountain Lion Finally, are there any good programs to clean up my mac so it runs faster? Thanks So much!!