Hello I have a hp pavilion computer. The motherboard went bad and I replaced it. The old motherboard was a A7N8X-LA. The new MB is an AU31. I know I cannot hook up the front panel to the computer, except for the USB. Using a hard drive I know works in another machine, I attempt to boot. It gets to the point where it asks If I want to start XP normally or safe mode etc. It does not matter which I choose, It flashes a blue screen more just a second and then begins to reboot. This cycle continues until the power is turned off. Any suggestions? Thank you Terry