When I shut down my Dell laptop , the power light stays on , screen goes off, no sound from fan or anything, but it does use its battery because after around four hours light goes off,, and without charging cannot open. If i want to really shut-down have to press the button and hold for few seconds. when restart it completely shut-down but does not restart. Its just around 3 months old. I cannot remove its battery, got inbuilt battery.What could be the problem , tried all possible things using windows help and internet. I have windows 7 installed.