I have two ASUS P4C800-E and Deluxe PC's running Windows 7 (both are 6+ years old)...one with an old ATI card and one with a Nvidia card...they both picked up the needed drivers
(sound, video, ACPI, etc) for everything without any problem.
Have you done a Windows Update yet?
Have you gone into Control Panel/Device Manager and done the Update Driver
on devices that are a problem?