If you are unable to install Silverlight on your PC due to administrative privilege settings, you can view the videos using windows media player which is pre-installed on your PC. Simply click on the link to the video you would like to view and then select the appropriate bandwidth link; the video will automatically play using windows media player.
If you are running Mac OSX on a non-intel computer, you will need to install the flip4mac plug-in
If you are using a Linux system please use the following link to install Moonlight. Moonlight is an open source implementation of Silverlight, primarily for Linux and other Unix/X11 based operating systems.