Starting today my Powerbook kept on freezing and 3 times words came up on the screen basically saying system failure. It never came up again now, only problem I have is it keeps freezing like after a few minutes I've turned it on. I saw another thread that it might mean my hard drive is fried?? How do I confirm this? Also I don't know how to back up my "life" from the Powerbook. Should I go to the Apple store and have them look at this or is it not worth my time?