Umm... LimeWire isn't a site. If you are playing a video then you are playing it from your own computer.

In general you cannot play incomplete AVI files. MPEG files can usually be played even if you only have part of it.

If you launch a video file from within LimeWire - this is identical to launching it from anywhere else on your computer. It is very difficult to see how it can play from within LimeWire but fail from elsewhere - unless you are trying to launch directly from a video player other than your system default one.

Given that I don't understand what your problem is - the best I can suggest is that you look for the Nimo codec pack (do a search in LimeWire (or google) for "Nimo codec") and install it.

Mark