Windows Media Player is Not Listed in OPEN WITH Right-Click Context Menu

Hello.

I have Vista Home Premium.

Can I please get some help with Windows Media Player?

For some reason, WMP has vanished from the OPEN WITH right-click
context menu for various files, such as WMA files.

Several other programs, such as Winamp and Real Player, are listed
there.

When I select Choose Default Program, WMP is not listed among the
recommended programs.

It's not even listed in the "Other Programs" area!

So, I choose BROWSE, and I locate the .exe file that launches Windows
Media Player.

This does not succeed in adding WMP to the context menu list.

Quite simply, I cannot get Windows Media Player added to any part of
that list.

Are there any other ways I can get WMP added to the Open With context
menu, without formatting and reinstalling Vista? (grin>

Thank you very much. Jd