How to change default media player on XP?

I want to change the default media player on Windows XP to Real Player. I think you in advance for any help.How to change default media player on XP?
When you install Real Player, it will ask you whether you want to make it the default player for all kinds of file extensions. That's faster than changing the default program for each file type one by one.How to change default media player on XP?
In the options for real player there is a place to set it as the default player by media type.
Right click the clip

a window will pop up.

click the change option and change it from wmp to real player.thats it!!