It may well be a codec issue. I'm not a great knowledge on WMP, but I could recommend a player that does play all b/c it has its own built in set of codecs & still with the option to downld more if needed. I'm refering to QCD: http://www.quinnware.com/

Perhaps you could see this also: http://www.microsoft.com/windows/win...cdownload.aspx & also this one: http://www.free-codecs.com/download/Nimo_Codec_Pack.htm