i have a custom built running windows xp, it has a asus p4p800 motherboard with a nvidia geforce 5700 video driver. this machine is a dino but very reliable. when i finished running windows updates i rebooted and the monitor now goes to sleep after the xp screen. tried to get into bios but the keyboard does not respond either. don't know what to do, ran other monitors on it with the same results. please help me save this old friend.