I was arguing with a senior manager at the apple store, had issues with my MBP and I was being honest and said that I changed my HD , he said you shouldn't have done that, I was like does it void the warranty he said yes I pointed out that in the MBP Manual it shows instructions , he said no it does not I said Yes he laughed and said NO seriously I have the manual in front of me right now I think I'll go back and show him the page 