Unless Windows knows the capabilities of your video controller and monitor, it's going to use something that's safe. You need to check your device manager for the video controller and see if it's unrecognized (yellow exclamation point). If it is, you need the proper driver and you need to find a way to get it. If your video controller is on the motherboard, it's probably on your motherboard driver disk. Once that's done you will be able to change the settings. For optimum compatibility, you try to find a driver specific for your monitor by make and model. That should do it.