Trax,

If you're using Windows 7 (64 bit), you can open the Control Panel and go to "Manage Audio Devices" under Hardware & Sound. If you change the default device under the Playback and Recording tabs to the Yamaha (instead of the built-in devices which are the default), the PC will use the Yamaha card. However, all Windows sounds will now only play thru the Yamaha, so you'll have to revert the default back to the internal devices or keep using the Yamaha output to hear anything.

With the older versions of Windows (XP or earlier), you had more flexibility in setting up sound sources in the O/S. I have the Roland SD-50 MIDI/Audio interface with its own ASIO driver, but if I want to listen to sound files on the net, I'm forced to listen thru the internal "default" hardware, unless I do the "re-direct" outlined above.

Dave R