1.) Download VLC Player and see if it's able to play the movie.
2.) If it plays download GSPOT to identify the missing codec.
3.) Keep in mind you may have to purchase third-party software as indicated here.
John
My system is Acer Aspire 5570z, 1.6ghz 512mb DDR and Win. Vista Home Edition. I am trying to use WMP to simply play a movie and i am getting the following "windows media player cannot play the DVD because a compatible DVD decoder is not installed on my computer." Yet each software :MPEG, AVI etc, the system says that vista already has the latest software installed. If so why will it not work???? grrrrr

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