what you need to do is install the HDMI driver....
I assume this has onboard video with a HDMI port...so when you install the onboard audio it also find the HDMI port (sound is in with the video) and it's telling you it cannot find the driver for the device....
two options...
1) disable the HD Audio (HDMI) via the bios or
2) install the HDMI driver off the motherboard CD....
you can just update the driver via the device manager and search the cd and it will find it....
But once it does install you may have to go into the sound properties to switch it back to onboard to get sound back....you can select onboard or HDMI sound but not both at the same time....
