There is no API for this. Can you elaborate on your scenario? We may have an alternate solution for you in Vista. Frank Yerrace This posting is provided "AS IS" with no warranties, and confers no rights. ________________________________ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of John Rennemeyer Sent: Thursday, July 06, 2006 8:37 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Setting Default Sound Device Programmatically in Vista Hi, I am looking for a way to programmatically set the sound device for playback in Windows Vista. In XP, you could set the SoundMapper registry setting "Playback" key to the name of the device you wanted the program to use as long as you set it before program startup. Once the program started, you could set the "Playback" key to a different device and have all the other applications use that device. This helps keep sound secluded for recording audio calls and things of that nature. The only caveat is that you couldn't use the mmsys.cpl to reset the device otherwise the program would default back to the device you set it back to once the program stopped outputting audio. Does anyone know if there is a registry key in Vista that will do the same thing as in XP? Thank you, John