Go here ad download the K-Lite Codecs pack (I'd choose the full version). Install it as instructed and then try to play your file with the Media Player Classic included in the pack. If you still can't play the file, use G-Spot (also included in the package) to get some information about the codecs needed to play the file, then google the codec name for free download...:
http://www.k-litecodecpack.com/ 