If you open the iTunes folder (Typically My Documents\My Music\Itunes Music) find one of the files and view the properties of the file (right click > properties). What does it say under "Type Of File"? If it says "MP3...." then you are in luck and it will import into any audio software. If it says m4p, then it is a protected file. It it says m4a, then you can probably import it into most programs (windows media player).
You may need to get a converter.
M4P to MP3 Converter
http://www.m4p-mp3.com/M4A to MP3 Converter
http://www.download.com/Magic-M4A-to-MP3-Converter/3000-2140_4-10726540.html?hhTest=1