After I downloaded a video file and tried to play it on Window Media Player, it was stretched out vertically, it resembled a totem pole, it was just 1 long column. I could hear the audio and only could see blurred colors and lines in the column. What just happened?

Did you preview the movie while it was downloading?
Might be a codec problem. Check below for links to codec packs. I've used the XP Codec Pack for WMP. You could also try VLC player...it's free & has codecs installed, it's very reliable. You'll find a link for download, plus more info within the link below
CODECs list for Movies /Alternate players / Video help forums

Always check a movie with Bitzi before download. If other users have rated the file, you'll get an idea of it's content & quality.
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