To start converting mp3 files, you need to right click on the mp3 files in Windows. Yes, you heard right…You start the program by right clicking on mp3 files in Windows.
For example, if you had a bunch of mp3 files in "C:\My Music", you would first double click "My Computer", followed by double clicking "(C:)", followed by double clicking the "My Music" folder. Select the mp3 files you want to convert. You can select the mp3 files by either dragging, or if you hold down the Ctrl key you can individually select them. Right click on one of the selected mp3 files and a menu will appear. Click "Convert mp3(s) to wave(s)…" and the program will start!
If you are still not quite sure how to start it, here is a highly compressed realvideo (142KB) which shows how to right click mp3s to start the conversion process.