technical help needed

Dear Internet,
 
I am stupid. Very stupid. I uploaded 3 songs onto the Taint's website in the .cda format (which is how they saved from the CD) but apparently when other people try and listen to them, Windows Media Player denies them.
 
I am stupid, but have figured out that I need to convert these files to .wav files or maybe .mp3 files. I am too stupid to know how to do that. I am stupid and cheap and am clucking my tongue at the thought of paying $20 for the software to convert these files.
 
Are you smart enough to help me convert these files somehow? Do you have some magic trick? Can I pay you in pirate lollipops and peanut butter bon bons?
 
I love you,
 
Mia