Jholland1964 is correct..

Could be the motherboard chipset driver for power management.. If you haven't already installed the factory driver set/utillities, best suggestion has already been made; Use your service tag to look up the appropriate downloads at dell.com

They should have drivers to cover the motherboard chipset, including power managment, lan, audio, video, special buttons and the touchpad, if it is equiped with one. If the laptop is currently configured as shipped from the factory, using the service tag to find support and downloads should get it going to factory specs, pay close attention to and follow the instructions listed at dell.com for installing their drivers/applications.