In Windows 7, your high-definition video may stop playing in Windows Media Center after reducing your video window from full screen but the Media Center controls still show the video is playing. “Media Center interacts with many system components including video drivers when maximizing and minimizing screen size and, depending on available system resources, may stop playing a high-definition video after repeated screen size changes but not update the Media Center controls.” To resolve, Click the Stop button to force the Media Center controls to update and then click the Start button to resume playing, infomred Microsoft in KB2001812.