Setting VLC as default media player ..
First go to the control panel in the start. Then go to “programs” and after that go to “default programs”.
In this you have go to the option of “set your default programs”.
Here you have to select the VLC on the left hand side and set it as default. After doing this setting, now you VLC will be set as the default one.
I think this may set all media (inc videos and audo) to open in VLC by default. But you can change the audio defaults to mediamonkey if you choose.
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For mediamonkey,
1. Go to Tools | Options | General | File Types and make sure that
the file types that you wish MediaMonkey to be used with are checked
off and that 'Re-associate File Types on startup' is checked off.
2. If another media player is still used by default, then it is usually
because that application has some sort of 'agent' that is configured to
always associate the application with Media Files.
o To stop Windows Media Player from doing this, click 'Set Program
Access and Defaults' from the Start menu. Locate 'Media Player' and
change the default application to 'MediaMonkey'.
o For other applications such as iTunes or Winamp, you'll need to go
into the program's configuration dialog and disable any functionality
that automatically re-associates the application with media files.
Note: on Windows 7, Vista, or XP, you can access the 'Default Programs'
option via the Start Menu to verify/validate file associations.
good luck, hope it works for you with above instructions