If your computer is running Windows XP and you have more than one digital media player installed, you can choose Windows Media Player 11 as your default digital media player for all the audio and video file types that it supports. This means that when you attempt to play a supported file type, such as Windows Media Audio (.wma) or Windows Media Video (.wmv), the Player opens automatically and plays the file.
For more information about the file types supported by Windows Media Player, see Windows Media Player multimedia file formats.
To set Windows Media Player 11 as your default digital media player
Open Control Panel.
Under Pick a category, click Add or Remove Programs.
In the Add or Remove Programs window, click Add or Remove Programs.
In the Add or Remove Programs dialog box, click Set Program Access and Defaults.
In the Choose a configuration box, double-click Custom.
In the Choose a default media player area, click Windows Media Player, and then click OK.
You also have the option of setting Windows Media Player as the default digital media player for one or more specific file types rather than for all audio and video file types that the Player supports.
On the Tools menu, click Options, and then click the File Types tab.
Select the check box of the file types you want to play in Windows Media Player.
The Player may not be able to play a file, even though you have selected its file type. This can happen if the file uses a codec that is not installed on your computer.
The Player can play other file types but cannot be set as the default player for them.
Clear the check box of the file types you do not want to play in Windows Media Player.
Clearing the check box next to a file type restores the file type association to the previous default player, if one was specified. If no default player was previously specified and you try to play a file, a Windows dialog box will be displayed so that you can select the program you want to play the file.
If a check box appears dimmed, the Player has only partial ownership of the file type. Multiple file name extensions are assigned to the file type, but the Player only plays some of those extensions by default. To give the Player full ownership of a file type, double-click the dimmed check box.
In some cases, you might set Windows Media Player as the default digital media player for a specific file type but a different player or program opens that file type instead.
This may happen for one of the following reasons:
Another program that competes for audio and video file types, for example .mp3 or .mpg, may have "taken over" that file type, even after you associated the file type with the Player. This program may use registry monitoring to maintain the file-type association. If this happens, you may be able to remove the file-type association in the other program. For more information, see the documentation for the program that has taken over the file-type association.
A program, such as a Web browser, may use its own file-type association methods to change the default program for a file type. In this case, you can use the configuration options provided by that program to change the file-type association back to Windows Media Player. For more information, see the documentation for that program.
In Windows Explorer, you may have used the Open With command to open a file with a different program, and on the Open With dialog box, you may have selected the Always use the selected program to open this kind of file check box. In this case, you can use the same Open With command to change the file-type association back to Windows Media Player. To do so, right-click a file, point to Open With, and then click Choose Program. On the Open With dialog box, click Windows Media Player, and then select the Always use the selected program to open this kind of file check box.