Check the Windows Control Panel -> Sounds tab, and see what Audio Output Devices are listed. If none are, check the option to show all non-active output devices [might be an advanced option].
I am having a similar issue, only with IDT Audio Codex. It seems to have happened because of a recent windows update. No output devices are listed, even with the non-active showing. In my case, this is the error I get when I look at the driver: Windows cannot verify the digital signature for the drivers required for this device