If you are looking for a freeware tool to convert audio files you can try this free audio converter for Windows 7 or check out the following tool that allows you to mass convert many different formats.

MuConv is capable of converting MP3, OGG, WAV, M4A, FLAC, WMA or AC files to MP3, Ogg, MPEG4 or WAV.

Mass convert audio files
The interface of MuConv is intuitive and allows you to add many files at once:

Decode with MPlayer (faster decoding)
You can either decode your audio files with the default codecs (Lame, Azid, etc) or you can decode the audio files with MPlayer which is a bit faster. (Supported formats: .wav;.mp3;.wma;.ogg;.m4a;.mpa;.mp4;.aac;.flac;.ac3;.avi;.mpg;.mov)

Audio tags
Additionally you can save audio file tags and add Artist, Title, Album, etc. to your audio information before converting them.

So, overall this is a easy-to-use, free tool that supports Windows 7 32-bit and 64-bit and should be one of the first choices to convert audio files.

Download MuConv
You can download the audio converter for free here: Download
Beta 3 has been released only 18 days ago.

Here’s the full list of possible audio conversions:

• FLAC to MP3
• FLAC to MPEG4
• FLAC to WAV
• FLAC to OGG
• WMA to MP3
• WMA to MPG4
• WMA to WAV
• WMA to OGG
• AC to MP3
• AC to MPG4
• AC to OGG
• AC to WAV
• M4A to MP3
• M4A to OGG
• M4A to WAV
• M4A to MPG4
• WAV to MP3
• WAV to OGG
• WAV to MPG4
• OGG to WAV
• OGG to MP3
• OGG to MPEG4
• MP3 to WAV
• MP3 to Ogg
• MP3 to MPEG4

• 
  Black Ops 2
• 
  Halo 4
• 
  God of War 4
• 
  Crysis 3