Hi
It sounds as though your computer is having some problems with the codecs it is using to play videos... It should play them OK as they are standard mpeg files...
You can download a new codec pack (k-lite) which contains all the commonly used codecs for video files, this should help you in playing the files.
Here is the link which takes you directly to the installation file needed... Download this file and install it on your system, and you should be able to then see the files.
http://www.free-codecs.com/download_sof ... =3905&s=95