Several AVI video files on my computer play perfectly, however when I take these files to a different computer they do not play, but instead only the audio component of the video plays. Is there something wrong with these videos preventing them from playing on the other computer?

When playing back media files on a computer (such as video or audio files) a particular codec is required for those files to correctly play. Codec stands for compressor-decompressor (or coder-decoder) which specifies the way which the media file has been encoded. Media files need to be encoded so that they can be digitally transmitted and saved onto digital media, such as hard drives and optical media (e.g. CDs, DVDs, etc.). The computers which encode the original media have the necessary codec installed, otherwise the media could not be encoded in the first place! Likewise, the computers which play back the media also need the same type of codec installed so that the media can be decoded and played back on the computer. In your case, it seems that your computer has the correct codec installed to play the movie (as it plays correctly on your computer) but the other computers on which you are attempting to play the movies have the correct audio codec but not the video codec, thus the video is not playing but the audio is playing. For the lay-person it is generally quite difficult to determine exactly what codec is being used for a particular media file, so generally it is much easier to just install all the common codecs or install a player application which has the most common codecs in-built. Fortunately, the free VLC Media Player comes with most codecs built into the player, therefore VLC Media Player can play most videos without any problem. I suggest that you download VLC Media Player (www.videolan.org/vlc) and install this on the other computers which should allow you to play the AVI files.