i have a dell laptop latitude model.After walking away from my computer and it being inactive for 20 to 30 min or if i close lid.When i try to start using it again or open lid and try to start using it.The laptop stutters,lags,and freezes repeatedly.If i restart laptop it runs fine even if i lets say play wow for a couple hours straight or watch some movies it runs fine until i leave it inactive again or close lid...any thoughts please.