Right click your desktop and look at "screen resolution". (if you use something other than windows 7, it may be under properties or desktop properties, I forget). Then increase your resolution to the max resolution you can which should be your naitive resolution for the monitor.
Then once you are in a game, you can select a larger resolution to max what your monitor uses as it's naitive resolution.
You are in fullscreen in these games, it's just the resolution you are choosing is smaller than the resolution supported by your monitor.
Did not work game and monitor are set to the same res.