Here are two good (and of course free) options for manipulating audio files.
dBpowerAMP lets you rip CDs, convert files, and record audio. It supports MP3, MP4, M4a, WMA, OGG, AAC, APE, FLAC, Apple Lossless, and more. This app integrates with Windows, so you can simply right-click on a file to convert it. Get it here: www.dbpoweramp.com
CDex is a CD-ripping and file-conversion app for the extremely picky. It includes many different encoders, including LAME MP3, Fraunhofer MP3, MP2, APE, OGG, WMA, WAV, VQF, and FAAC. It also has jitter correction for error-free CD ripping and works with the CDDB database. Get it here: http://sourceforge.net/projects/cdexos
MelodyCan is a universal audio file converter, which supports all popular audio formats: wav, mp3 (MPEG Layer-3), wma (Windows Media Audio) etc. This software allowas you to convert
drm protected and non-protected file formats. Moreover MelodyCan converts audio books, any format Media Player,
any format QuickTime Player, any format Rhapsody or RealPlayer supports. This software is easy to install and use
with a very handy and clear user interface. You can try free trial version ~> http://www.melodycan.com/download_page.html
well done, man