Hello so I own a Dell D531, I bought it last year for doing basic stuff like web surfing and youtube watching, but I really can't use it for any of that because the cpu decided to always run at 798mhz when unplug it and it only does it when unplug it, runs good when it plug in. I had worked on may dells and other brands but never had encountered something so irritating about a laptop in my life. I hope someone can help me or answer why it does this, and if it a dell thing and can't be resolved then I can only sell it for parts since it pretty useless when it runs at 798mhz when you unplug it.