I have a Dell Dimension 2350 and when I left the house this morning it was working and I left it on. When I came home from work I notice that it was off. I powered it on and it won't boot pass the win xp logo screen. It just powers off. I keep trying but it just doesn't go pass the logo screen. I tried to start it in the safe mode but it would shut down before it could go into safe mode. Please tell me what could be wrong and what should I do?