1)
Download and install version of CDex. CDex is absolutely legal and 100% free software. You can also find it at www.download.com

2)
Press the "Configure" button.

3)
Choose a "Filenames" registry and set up a destination directory for the converted WAV files. Press "OK".

4)
Press the "MP3 to WAV" button.

5)
1. Choose the directory that has your MP3 files
2. Select all of MP3 files that you want to convert
3. Press the "Convert" Button.

The decoding process takes usually 2-10 minutes.

Converted WAV files will appear in the directory that was set up in step 3)