I have newly installed Video Card ,EVGA 7600GT, 512MB, AGP. But now Windows Media Player 11 will not play DVD

I t plays CD's but not dvd. Old video card was 128 mb ATi Radeon w/ Hydrovision. Any Ideas why this is happening & what to do to fix it.|||Well did it play dvds before? Because if it didn't you probably don't have a decoder for windows media player, so just download avs dvd player from snapfiles.com or somewhere, that will work for you.