ADPCM codecs have been included since Win95, so any Windows transcoder that uses ACM should be able to do the job.

This paper presents the Adaptive Differential Pulse Code Modulation (ADPCM) method of digitally storing and reproducing speech or other waveforms. A detailed explanation of the encoding steps is given ...

Hi,<BR><BR>I've got a 4-bit WAV that's resisting my attempts to decode. I've tried uLAW, aLAW, and VOX ADPCM without luck. I've also tried to open it with the proprietary X-Box ADPCM and Dreamcast CDI ...