HOW DO I TURN A REGULAR MUSIC FILE INTO A MP3 FILE

From North Philly, 1 post

I TOOK A CD AND RIPPED IT TO MY COMPUTER AND I AM TRYING TO UPLOAD IT TO A WEBSITE SO I CAN LET OTHER PEOPLE LISTEN TO MY MUSIC BUT THE SITE SAYS I CAN ONLY UPLOAD MP3 FILES BUT IN ORDER TO DO THAT I MUST CHANGE THIS MUSIC FILE INTO A MP3. HOW?

From Uk, 1 post

go to

http://www.nch.com.au/wavepad/
where you will find a free download which will do what you want plus lots more