1. Right-click on any open space on your desktop.

2. You should be presented with a menu like the one shown below.

3. Click on the 'Screen resolution' menu item.

4. A window similar to the one to the right should appear.

5. Click on the resolution drop-down menu and select the desired screen resolution.

6. Once you have selected the desired resolution, be sure to click apply. Now you can close the window by clicking OK or the red X in the upper right corner of the window.