When you try to extend the desktop to a secondary display while Windows Media Player is playing a video on the primary display, you may experience one or more of the following symptoms:
Although the sound continues to play, the video may be missing.
The video may stop, and when you try to start it again, you may receive an error message, or it may play sound without a video.
These symptoms may also occur when one of the following scenarios is true:
You try to turn off the extended desktop on the secondary monitor while video is playing.
You are using a third-party video playback program other than Windows Media Player.
This problem is caused by a limitation of Microsoft DirectDraw.
To work around this issue, use one of the following methods:
After you turn off or turn on the extended desktop to the secondary display, stop your video playback program and then start it again.
Turn off or turn on the extended desktop before you start the video playback.
Try to make the video play in full-screen mode.
Move or rotate the monitor before you start the video playback.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.