...Two separate drivers need to be installed for such sound.. First, see if there is an "Audio BUS" driver available at the computer manufacturer's website to go along with the standard audio driver. Uninstall any current audio drivers installed, then install the BUS driver first, then install the standard audio driver.
I recently used combofix and lost my sound. It says that the multimedia audio controller is not installed. I can't seem to find the correct driver. Apparantly it takes more than one step. Can anyone help?