GeoVision videos are recorded in the proprietary Geovision video codec. What this means is that they will not be playable by default on another PC. It may play on your PC if you have the codec installed, but generally the public will not be able to view the files.
One way around this is to use a program to convert the video files from the Geovision codec to the Microsoft Mpeg4 codec. This is useful if you need to give the file to the police, your business associates and your attorney after an incident.