to download and install the latest DivX codec, for windows media player that is. If you're using something else, I'd follow LOTR's advise only for now. AVI's use the DivX codecs, and DivX 5 is the latest that is easily acceptable. The bundle comes with DivX Player 2.0, but you don't have to use it. Follow the instructions for installing the codec, and bingo.. any avi file should play. Course, there are those with 128mb ram on their systems, so just be aware if you have a system with less than 256mb ram you could get "dragging" replay. You can find the DivX codec at any number of sites, just beware of the type of sites you get your stuff from.. umm duh. Take care.