Since WMP does not have DVD decoding you must install the DVD software player and then try to play the DVD with WMP and hope it works out.
Best of luck,
We have installed a generic DVD player on a WinMe machine. The software that came with the player works but... On my one machine running XP we get better and more user friendly results using Windows Media Player. Both machines are using Media Player 9. Any help would be greatly apreciated. I will post this in hardware forum also.