Use an audio manipulation tool... or insert it into an video editor and export... There is a million ways to do it...
Try using windows movie maker... export it in .wmv and remane it to .wma dont you have any video audio manipilation apps?
EDIT
Typo Dont
If the wma rename works you then can try converting it to an mp3 or WAV or OGG even...
I buy a lot of software and over the years tallyed over £2500 in purchases some of which I barely got used to... so have something for everything... what I do not like is a software firm charding you full rate for an upgrade that brings very little in difference...