I have a Gigabyte GA-Z77X-UD5H and Windows 8 64 bit. The PC has been shutting down fine with an old monitor connected via VGA to a R9 280X GPU. I've now installed a new Viewsonic VP2770 monitor via DVI. When I shut down, the PC now restarts instead. Is there a BIOS setting or Windows 8 setting to ensure the PC shuts down correctly?