I personally use the Media Player Classic; it comes as part of the K-Lite Codec Packs, Standard, Full, and Mega options. I have used this in place of the WMP for years and have had no problems in playing any of the media I have used so far. I use the Mega option, if only to be prepared for any new or old formats or codecs I may need to use. The player and the codecs are free and can be found at:
http://www.codecguide.com/download_kl.htm
Perhaps this may solve some of your media issues...
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