Please edit out you email addy, you might get some freaks spamming you and it's against the forum rules to post it...
Your problem sounds like a codec issue, you will either need to install the correct codecs for your existing player's or just download the VLC player, it's highly recommended here and has all the codecs already installed and it's free...This sticky has all the info and download links you will need...
CODECs list for Movies/Alternate players / Video help forums/ video-mp3 fixers