I guess I really screwed up... I got to Windows XP part of my MacBook pro I was trying to activate my xp account but it says my ID is invalid now I can't even go back to Mac OS X. Is there a button or something I can do on start up so that my Mbp starts in mac os x instead of so? HELP!!!!! Btw I'm writting this from my iphone since I can't use my laptop!