I try to turn on computer it freezes during startup and there is nothing I can do so I turn off the power and turn it back on and try again, then it does it agaiun and again and again, then hopfully it sometimes finally works then i get to like the part where I click my user name, and it just freezes again and I do that over and over, I might finnaly get on comp like I am right now for about an hr or so if i am lucky and then for no reason it turns off and goes back on. Its not my power connection, so what could it be and what can I do?