Minimize all open windows so you can view your desktop screen.

 Place the cursor on any empty spot of the desktop screen and click the right button of your mouse.

 Place the cursor at the bottom of the box, over 'Properties' and click the left mouse button.

 At the top of the new box, place cursor over the tab 'Settings' and click left mouse button.

 On the slider for Screen Resolution, place cursor on slider, holding left mouse button down, and drag slider to the far left until the screen resolution indicates 800x600.

 Place cursor on 'Apply' button and click left mouse button. A dialog box will appear asking if you wish to change the settings, click on Yes.

 The screen will flicker as new screen resolution is setting. The resolution will remain set at 800x600 until you change it back to whatever setting you prefer.