My brother gave me his old Macbook 4,2 for me to use for school since my laptop died earlier this year and he just bought himself a brand new Macbook Air. The hard drive is failing (get a lot of errors trying to copy his stuff off) so I am going to buy a 320GB 2.5" SATA drive from the local store today and had a question on installing Snow Leopard / Lion onto the newly purchased hard drive. My brother doesn't have the installation discs that came with his Macbook and I was wondering what the best way to go about installing OSX onto this new hard drive? Is there something I can do with the old drive to install its image of OSX onto the new hard drive? Thanks in advance!