Hi All, I have a USB device that exposes headset input and output terminals. I use "SetupPreferredAudioDevices" keyword in my inf to designate it as the OS default playback and record device. The inf works fine in XP 32 bit SP2 and XP 64 bit SP1. But when it comes to XP 32 bit SP3, it doesn't seem to work at all. To experiment, I tried on 2 devices with inbox driver. One is headset device and one is a "speaker" device. When both devices plug into the OS for the first time, the Speaker device will automatically become the default device over the onboard HD audio device. But when the headset device is plugged in, the onboard HD audio device stays as the default. I seem to have the same behaviour on Vista SP2. Is this the correct behavior or is there any other way to set a headset device as the default sound device in XP SP3 and Vista SP2? Thank you. Angela _________________________________________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. https://signup.live.com/signup.aspx?id=60969