Windows might not always detect your Monitor accurately. This affects display and refresh rates. To select your monitor manually: 1. Right-click on the Desktop. 2. Choose Properties from the context menu. On the Settings tab press Advanced button. Select the Monitor tab. If your monitor is not listed (correctly) here, click on Change. 3.Select your Monitor form the list, or if you have a driver disk for your monitor, select have Disk. 4. Click Apply, and follow any other instructions on screen.