If you are attempting to play an embedded QuickTime file (.mov) and it appears to be loading forever the chances are that you do not have QuickTime or the proper plugin for your browser installed. You can check if your browser is functioning properly by visiting this link here. If that movie plays correctly then your QuickTime plugin is functioning properly.
If the movie does not I suggest installing QuickTime by downloading it here. Please note that unless you want iTunes installed as well you should click the second radial button to install QuickTime only. Once downloaded double click the installation file and follow the guide to install QuickTime.