How to Install CCCP Codec Pack.
This video briefly goes through installing and setting up CCCP Codec pack.
Codec packs can help resolve issues with files playing back incorrectly or not at all.
And here's a couple of free media players :
VLC : http://www.videolan.org/vlc/ : Install walkthrough : • How to Install and configure VLC
WinAmp : http://www.winamp.com/ : Install walkthrough : • How to Install and Setup WinAmp