You are using Windows Media Center to play a .wmv file in full-screen mode. You press the Windows logo key to switch the focus from Windows Media Center to other applications or to the desktop. However, when you switch the focus back to Windows Media Center, the Windows Media Center screen sometimes remains blank.
You are using Windows Media Center to play a .wmv file or a MPEG2 file (.mpg) in full-screen mode. You press ALT+TAB several times to switch the focus back to Media Center when the movie is running. When you switch the focus back to Windows Media Center from other applications or from the desktop, you receive a "Cannot Play Video" error message.
You are using Windows Media Center to play a .mpg file in full-screen mode. When you change the focus from Windows Media Center to the desktop, Windows Media Center crashes.
You attach a CRT monitor or any other external monitor to a Lenovo ThinkPad portable computer. You play back a DVD movie in Windows Media Center, and then you switch the movie to full-screen mode. When you press Fn+ F7 to switch from the LCD monitor to the external monitor, the external monitor sometimes displays a black screen.
External CRT monitors connected to Lenovo portable systems
This article is based on a Microsoft KB 946464.For more information please visit the below given link