How can I play DVDs in Windows Media Player (WMP)?
To play DVDs in Windows Media Player (9, 10 or 11) you need a MPEG-2 decoder that is capable of decoding DVD video and is also compatible with WMP. The K-Lite (Mega) Codec Pack contains a compatible decoder. Some examples of compatible decoders are: Cyberlink, DScaler5, InterVideo, MainConcept and nVidia PureVideo.