Did you see a movie appear above? Is there a red apple there? If so, you have QuickTime installed! Right click on the apple and open "About Quicktime Plug-in." This will display another window telling you the "Plug-in version" that you are running (Independent Study suggests 6.5+). If you are running an older version of Quicktime, if Windows Media Player tried to play the file, or if you see anything other than an apple above, close this window and see "How do I uninstall then reinstall QuickTime?" on the questions page.