Hi Paul, For Vista and later platforms, you can use PKEY_AudioEngine_OEMFormat in the INF file to do this. This is documented in the WDK under Media-Class INF Extensions (http://msdn.microsoft.com/en-us/library/windows/hardware/ff537752(v=vs.85).aspx). Jeff From: Paul Titchener Sent: Sunday, July 01, 2012 8:07 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] How to set a driver's default sampling frequency and num channels I’m working on creating an installation .inf file for a wdm audio driver. How do you set the initial sampling rate, number of bits and number of channels for an audio device driver? Can it be set in the installation script (preferable) or is it set somehow in the build of the driver?