Opening windows media center

When i open media center 2005, update rollup 2, a dialogue box appears saying "your video card or drivers are not compatible with Media Center". This was not coming earlier. I notice it now a days.when i click "ok" to the dialogue box the media centre opens. it plays songs but no videos Whereas window media player plays both. The only thing i did was automatic update of softwares and drivers etc as available in manufacturer's(hp) and microsoft's site. The notebook is "hp pavilion dv 2124tu" .