Video's
 

When I download a video, the audio plays fine but the video does not play. Is there anyway to fix this problem?

You need some codecs for the files to play properly.

For WMP try K-Litecode Codec Pack or XP Codec Pack 2.0.6.

Or try using VLC media player, it has the codecs built in and will play most file types. It's a good player to have around as a backup.

See: CODECs list for Movies/Alternate players / Video help forums/ video-mp3 fixers

Additional (Hopefully useful) information:

Before d/loading videos, check them with Bitzi Web Lookup. It'll help you sort out the good ones. While on the Bitzi site, search for the file there and use the magnet link to start the d/load in limewire. Then search for it again in LW to help find some sources for the file.
Also preview the file when it gets to 10-15% to check that it's what the title says and not mislabeled porn.

See: Fake files showing up in search results

Also: Problems with the search

How to find music(and video)