The only way I can get my computer to start is to cut, then restore power. Then I get the beep, and the Windows introduction graphics start showing up. Then the machine abruptly shuts down and the green led blinks 3 sec on, 3 sec off. The next time I cut and restore power, I may get a screen that offers to "restore". That option may or may not work. If it does work, the computer finally boots and acts normally. Or I might get a screen giving me the option to repair or start normally. Choosing to start normally usually works. What do I need to do?