In the normal booting sequence, just before the Windows screen appears there is a blinking cursor in the upper L hand corner of the screen. Once in a while the system hangs at that cursor, but then boots normally when rebooted. So 3 questions: 1)What is likely to be the cause of the current behavior 2) If one day the computer stops at the blinking cursor and doesn’t boot at all, what is the likely cause 3) If that happens what would be the steps to take