You can also tell it not to hide resolutions your monitor doesn't support and pick from that list. Just make sure your monitor can actually handle them. The reason windows is hiding those is because you don't have a proper monitor file/driver so windows assumes it can only support smaller, older resolutions.
yep. 1600x1200 is just not widescreen. very common years ago. as others stated, please make sure you have installed all your video and chipset drivers. look in computer management > device manager and look for yellow <!> warnings. Install correct drivers until all warnings are gone.