You can install codec or use a converter to convert it to some other format that you player supports. Maybe you can try uSeesoft Total Video Converter. It can convert video files between almost any format, like AVI, WMV, MP4, FLV, MPEG, 3GP, MKV, MOV,etc. As to extract audio files, uSeesoft Total Video Converter can extract audio tracks and convert to audio formats,such as converting MP4 to MP3, converting AVI to WMA, converting MKV to AAC, converting MP4 to AC3, etc.
Learn more details about it here: http://www.useesoft.com/video-converters/total-video-converter.html