Just a short comment from Microsoft about “Stereo Mix” for Conexant High Definition Smart Audio under Windows Vista.
As we know the Conexant High Definition Smart Audio is built in sound chipset so that it’s hardware capability is very limited. On the other hand, its manufacturer, Conexant, also does not plan to built powerful driver support for it. Therefore, its recording feature is very limited. (Please understand that the recording feature Must be developed in the sound device driver. The Operating System only provide the platform to link it with other programs.)
Based on the current situation, I am sorry to say that Microsoft will not be able to help you on this issue as it is a hardware problem. Please be assured that our Product Team will forward the customer feedbacks to Conexant in the conference call. However, it will be Conexant to decide whether or not to add the features in the sound card driver.