I was checking a laptop for a friend, and in the process, I did a web-based MS update. I also updated some hardware drivers (given that they were in the hardware section of the MS update screen).

Well, that caused the sound driver to stop working. (code 10 in device manager). I tried to download the latest sis 7012 driver, but that didn’t work… I eventually decided to uninstall the sis7012 driver, and roll back the realtek ac97 driver, and that finally worked…

Its can sometimes be very difficult to identify the correct hardware device on a PC (particularly laptops)