Ok, so I'm new to Macs and I just got a Macbook Pro 17". The only problem is I bought it used and it didn't come with the OS X install discs. I want to start with a fresh system and I'm not sure how to do it. I'm working on downloading the install discs off the pirate bay, but I want to make sure that the install is legit and will activate properly. Is there anything I have to do to make sure it works properly. Thanks in advance for the help.