Videos on this site are created using the emulator DOSBox. DOSBox records the video using a lossless video codec called ZMBV. This means that the video that you download will look exactly the same as what was being seen on the screen when the game was played. The sound however, has been encoded in MP3 to reduce the file size to a manageable level. In order to view the videos, you will need to have the ZMBV, and MP3 codecs installed on your computer. The ZMBV codec is installed when installing the latest version of DOSBox, or you can download it below. The MP3 codec is a standard codec in most recent Windows versions.
Download ZMBV Codec - unzip, right click on zmbv.inf and choose install.