Okay, see if it is listed in Device Manager. If it is, right-click on it and choose Disable. If it's not, or it is but shows as Video (VGA) Controller, try this: install the IGP's video driver (seriously), then go into Display Properties, right-click on its monitor and uncheck Attached. You may or may not have to disable it in Device Manager as well.
Good luck! I'm off to California in the morning for five days. I hope this gets resolved.