I downloaded some clips in avi. After tryiing Realplayer, Window Media Player, and InterVideo WinDVD player; I can only get audio from some of the avi files. (e.g. RealPlayer will say "some portion of the file cannot be played...etc." And there is no RealPlayer components to download to resolve the issue after the auto RealPlayer on-line search. Could it be the problem in the files or I need to use a different player on my PC.
AVI is just a container format. It was created by MS as such windows/windows media player supports avi fine out of the box. Your problem is because as I said avi is just a container. Use something like GSpot to see what video it contains and then install it.