Help convert .wav file to mp3 file ?

I just got done making a short version of a song with Audacity 1.3 Beta, it's a legit working .wav file, but the site I'm having problems with converting the wav file to an mp3 on a site called mediaconverter.org. May I remind you that the the wav file is working and legit, but when I put the file in to convert it, it keeps saying "C:\fakepath\Braveheart TV Size.wav". The file is not converting from a removable disc that I know of. anyway, as the download starts up, the download stops in the middle of it (the download bar goes half-way and then goes backwards and does not continue the conversion). If there are any ways to fix this or if there are any other better file conversion sources than this, please let me know, I would gladly appreciate it, thank you.