Ok my macbook pro, loads then all the sudden black screen saying someone elses NAME / PW. Officially my macbook has been hacked can someone possibly tell me how you would reinstall Tiger OS X before it loads through all the junk when you power it on. I really need to try reinstalling this or just anything. I already just lost over hours of footage, graphics for my new website I was working on. I have a ton of stuff backed up on a external but a lot of stuff I left on my laptop which im screwed.