Click on the video you would like to watch.
How to watch the videos?
In general as long as your software is up to date, it should be OK - so on windows, make sure your windows media player is up to date http://windows.microsoft.com/en-us/windows/download-windows-media-player, or on mac, check your quicktime player http://www.apple.com/nz/quicktime/download/ should cover most of the issues.