I migrated my Windows installation from my old machine (with a SigmaTel audio controller) to my new machine (with an IDT audio controller).
Both the SigmaTel controller and the IDT controller work with the standard Windows HD audio driver. However, to gain access to additional functionality, like the ability to switch the input port between “microphone” mode and “line in” mode, a more specific driver is required.
When trying to install the IDT driver, it insisted that I must first uninstall the SigmaTel driver with the error message:
The SigmaTel audio driver must be removed. Please uninstall the SigmaTel audio driver from the system and then run this installer again.
My SigmaTel device is no longer present and I was not able to find anything in “Uninstall” programs list related to it. Using Process Monitor, I noticed that the IDT installer was checking:
Deleting this registry key solved the problem.