Need Help Getting RealPlayer to Back Off!

Question

Previously all my video clips were stored with a QuickTime icon on them... and when I clicked on them to view --they ran thru QT. But somehow/somewhere RealPlayer has TAKEN OVER all my video clips (which now appears as a white blank page of an icon) and when I click them to play them --they play thru RealPlayer.
That wouldn't be so bad but, RealPlayer (at least the free version I have) won't "loop" the video clips. I spent nearly an hour today texting with a RealPlayer tech to find that out!
SO, does ANYONE know how to make QuickTime the 'ranking' player of my video clips again, like it used to be?
Some setting must have changed somewhere, and I'd like to set it back the way it was before.

Answer 1

[Mac OS X: Double-Clicking a File Opens the Wrong Application|http://support.apple.com/kb/TS2291?viewlocale=en_US]
*Changing the application used to open all files of a certain kind*
1) In a Finder window highlight a file of the kind you want to change the application to open that kind of file.
2) While that file is highlighted, select File > Get Info or press command (apple or propeller icon) + i to get a file information window.
3) In the lower part of the info window there is an "open with" menu with a list of applications.
4) If your application is already in the box then it is the default application for opening that kind of file and you don't need to do anything more. Close the get info window.
5) If the application showing in the menu is not the one with which you wish to open the file then select a new application. If your application does not appear there then select the "other..." and track down the application (usually in the Applications folder at the main level of the computer).
6) If you wish to change all files of this type to open with this application in future, make sure the "change all" button is selected.
7) Close the get info window.
[10.4: Enable 'Open With for all' to work for certain apps|http://www.macosxhints.com/article.php?story=20051104055843452] - Problem applications where the standard application assignment routine doesn't work.