Windows Media Player cannot switch to full screen. You might
encounter this error message for one of the following reasons:
The Windows display settings are not configured to support full
screen. In the Display Control Panel item, try setting
Hardware acceleration to Full. For more information
about display settings, see Windows Help.
Your video device might require an updated driver. To determine
if an updated driver is available, see the Windows Update Web page at the Microsoft Web
site, or see the video device manufacturer's Web site.