You probably have a widescreen monitor or a monitor that supports better resolutions. Use the preferred resolution for your monitor and then use Windows settings to change text and icon sizes. (or if need 800x600 get glasses)
That's a NEC 17" monitor with a native resolution of 1,280 x 1,024.
You should be using a minimum of 1024x768 on a 17" LED monitor.
800x600 uses only about 60% of the monitor's available pixels and as well blows things up very large. Glasses was a joke.