This is the graphics settings.
The graphic's settings can be accessed by pressing the ESC key.
There are several settings here which will affect the look of your game. First there is the Fullscreen button just under Resolution, this will make your game fill up the entire screen including the taskbar. To tab out you can press Crtl+Alt+Delete or press the Start button key.
Next there is the Resolution settings under the Fullscreen button, these detirmine the size of your game window, you can find your computer screen resoultion by going to the following directory:
Control Panel\Appearance and Personalization\Display\Screen Resolution
Quality Level refers to the quality of your game, higher levels will make your computer run slower but also make the game look better, adjust these to your own preferances.