When I dowload a movie thats "avi" type and when it finishes it only shows as audio (no image) when i play it can you make it show the image?

Sounds like you might need codecs for whatever player you're using. Have a look here for links to lots of different codec packs.
CODECs list for Movies/Audio/ Alternate players / Video help forums/ video-mp3 fixers

Within that thread is a link to download VLC player...it's free & has codecs installed to play most file types. It's a very reliable player