If you are looking for a great audio conversion tool, I can highly recommend dbpoweramp. It's $18, so it won't break the bank. It includes
an excellent .mp3 encoder (LAME 3.97), and also encodes .mp4 files.
It can encode and decode many other formats too such as Shorten and Flac. http://www.dbpoweramp.com/
. Itunes includes an .mp3 encoder but it sucks. I spent a lot of time looking for a great
.mp3 encoder for XP and dbpoweramp was very well reviewed so I tried it and found it well worth the money.