MP3 Sound Format audio files

[ahgute]

I recently downloaded some audio files that are in MP3 Sound Format. I tried playing the files with Windows Media Player, but couldn't because according to Windows Media Player I didn't have the necessary codec to play these files. Now, forgive my ignorance, but is there a difference between MP3 Sound Format files and .mp3 files? If so, where can I get the codec to the play these files, or is there a way to convert these files so they can be played with Windows Media Player? All help appreciated!

[PurpleDemon]

Where did you download them from?
Some places need their player to play and burn.

[ahgute]

I downloaded them through a peer-to-peer network. If I remember correctly, the folder where the files were located also had a link to a website where I could obtain the password needed to obtain the proper codec in order to play the audio files.