Hi, I've decided to completely erase my hard drive and reinstall Mac OS X. I'll be backing up my most important files to a friend's Time Capsule via ethernet (he'll give it to me for that day). I've done some research and come across this page http://support.apple.com/kb/ht3910 and noticed that it says along the top: "MacBook (13-inch, Late 2009)". My MacBook is from May 2009 (I got in October '09 but it's serial number says it was from May 2009) and I just had a look in it's box. It comes with a Snow Leopard Disc AND a Mac OS X Install DVD for "Mac OS version 10.5.6" (which I'm guessing is Leopard). When I first got my MacBook in October 2009, I just opened it, filled in my info like you normally would then I inserted the Snow Leopard disc and upgraded. Which disk would I use? Would I use the gray Leopard disc (10.5.6) or the Snow Leopard disc? I have a feeling it should be Leopard but I'm not entirely sure. Thank you!