i was using my Macbook i had 3 programs running imovie limewire internet, my imovie was not responding so i held down the power button to shut it off and thats whwn it all started. The next time i tried to turn it on i logged in with my password and then the only thing that was up was my screen saver on the desk top no programs just a blank desktop. I tried safe boot and other start up methods but nothing worked. I heard something about having to reinstall again with the discs but i dont know how to do that can someone help me with all of this.