Your not supposed to name the files, it's part of the
Forum Rules
You probably need to download the right codecs to play that file.
XP Codec Pack 1.3.0 is supposed to be a good one for WMP.
You could also d/l another media player.
VLC media player is a good one that has the codecs built in and will play most file types.
Go to this thread for more on info:
CODECs list for Movies /Alternate players / Video help forums