This may be the type of thing you are after
You can add new features such as audio and video effects, new rendering types, visualizations and much more by downloading plug-ins for Windows Media Player 9 Series or later. After you've downloaded a plug-in, you can find it in Windows Media Player under the View menu.
I just did a quick search on Microsoft using search words "dvd player" -the above was one of the results from this search -here is a link to the rest
You could refine this search to bring it down to a smaller number of results
My wife gave me 2 dvd's with movies of old music and every time I try to play it in my Win XP I get a "must install a dvd decoder".
I thought that Win Xp came with a dvd player. Do I need to purchase one or is there a Microsoft free install ?