The PCI device is referring to something connected to the pci bus or pci socket......

note...even on-board devices like sound and built in video are concidered PCI devices as they are on that BUS.

If you are showing an unknown PCI device and you are having issues with your sound card then I would believe that you are trying to install the wrong driver for the hardware that is installed or the device is whacked and will not accept the driver.

Google for Unknown device identifier and use that application to find and ID the installed device.