Not enough access privlages to change default player

Hi. All of a sudden, I cannot change the default player for audio files.
It's been iTunes for a long time and I've never had any problems with
it, but suddenly iTunes began telling me that I didn't have enough
access privlages to change the default player. It's not just iTunes,
because I can't change the defaults for any file type from the
right-click menu. I am on the Adminstrator account of a Windows XP
computer, if that helps. Thanks in advance for any assistance you may
be able to provide.


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