How do I reset streaming video file player in Firefox 27?

[DWD - Belize]

I accidentally accepted that all video or streaming files get run in RealPlayer. Now when I visit certain websites that stream in Windows Media Player, I get only sound but now video in RealPlayer. How can I undo my selection and correct my situation?

[abin]

1.At the top of the Firefox window, click on the Firefox button and then select Options
2.Select the Applications panel.
3.The Applications panel will display. Select the type of file for which you want to change the default action.
Multiple entries for the same file format or extension? Some file types can include more than one Internet Media type.
4.The Action column will give you a drop-down menu, with options on action to take, whenever you click that type of file.
5. Change every file type with Real Player to 'Always Ask' or 'Windows Media Player'.