Go to your WinAMP configuration, and in the list tree, Plug-ins>Output. Highlight "Nullsoft Disk Writer Plug-in v1.0". And click the button "configure" below to tell WinAMP where to put the WAV file. Be careful though, make sure you change the Output plugin back to "waveOut" after decoding, else you will not hear any music, and your hard drive will fill up with WAV files
