I'm trying to use Creative Centrale to convert my video files but everytime I try it comes up with "Convert Unsuccesful - The video codec required for the conversion is not installed." I've tried converting my files into Zen MX friendly videos but nothing works... I've tried various conversion tools but Centrale will not convert! It doesn't matter how precise my conversions are. Please help!

Audio Players & Recorders - Creative Labs - Zen Digital Media Player