If you receive the message, "This waveform-audio format is unsupported by your audio driver", try opening the recorder, click View/Options, select playback, under Confidence Monitoring make sure it is set to your Windows sound card (e.g. Soundmax or Realtek), and click OK. Then close and reopen the recorder. Do you get the same error? You can also try resetting the USB encoder (e.g. MAYA44 USB+). Just unplug and re-plug the device.