Lukas108, you can choose any system resolution you like but the options available from the factory will have black bars i.e. they won't take up the whole screen. The key advantage of following the tutorial or using the regkey hack is that it will allow you to choose lower system resolutions that do not have black bars on the top/bottom or sides - they are 3:2 aspect ratio just like the native screen rather than 16:9 aspect ratio. How the game chooses to render content on such a screen resolution is really up to the game, and if it still looks like crap, you need to provide feedback to the game developer. Most gamers use standard resolutions like 1366x768, 1600x900, or 1920x1080.