Hi, I am about to buy a refurb macbook pro 2gb ram and 160gb hard drive. I think I might need a bigger hard drive but i dont want to spend the money at this time. If I find (once I get to know my first mac) that I need a bigger hard drive I dont have a problem buying one and installing it. My question is once I install the new hard drive will my mac remember anything or is it all stored on the hard drive? Thanks for the help!