When it is playing video content such as a DVD, the operating system has to synchronize playback with the display redraw rate.
There may be a noticeable horizontal line at the point where the two frames meet. This is more noticeable during scenes that contain fast motion. This problem occurs because of a hardware limitation that is known as 'tearing.' Tearing is a video artifact in which the top portion of the screen shows a different frame of video than the bottom portion. In this scenario, you notice a cut line in the video on one of the monitors.
You play a DVD movie in Windows Media Player or a third-party video application. Your display is not set to use Windows Aero. You have the Duplicate (Clone Mode) display configured. Your computer supports two or more monitors. You have a computer that is running Windows Vista or a later Windows operating system.
