Your Windows operating system allows you to change the screen-size resolution. Monitors, depending on their shape and size, require different screen resolutions. This Windows resolution-setting feature comes in handy when you have switched out your monitor. It takes a few moments to set your resolution.
Click the "Start" button in the lower-left corner of the desktop.
Click "Control Panel" and choose "Appearance and Personalization." Select "Adjust Screen Resolution."
Click the slider and move it down to "800 x 600" and click the "Apply" button.
Click "Keep" in the dialog box that appears.