library deleted, will not recognize files - wmp 11 vista

when trying to start wmp 11 for vista an error message popped up saying that
there was some sort of problem and that it simply had to be restarted to be
fixed. once i restarted it, my library was entirely gone and i cannot seem
to transfer files from my music folders back into the wmp library. anyone
else encounter this/know how to fix it?
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boozeois