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.
Once installed then visit the link above to test the embedded QuickTime movie.
You may be prompted with the below at which time you should check the “Do not prompt me in the future.” check box and click “No”.
Prompt Message: “Some of the MIME types previously associated with the QuickTime plugin are currently associated with other applications. Should I restore these MIME type associations to QuickTime?”
That should be all that you need to do. All embedded .mov files should now play properly in your browser.