yes... let me find the link...
edit//
I will just exlain this to u...
1. u go to my computer
2. u go to the tools tab and click on folder options
3. click on the view tab
4. scroll to where the hide extensions are
5. uncheck it and click on
6. Go to the place where your song is and rename it (ex. erase mp3 and change that to wma) hope this helped

edit again//
u can do either alvins way or mine but i still think mine is easier