I will. I take it Windows will install drivers if the onboard sound isn't disabled?
What about the sound with the graphics card should that be just disabled?
Yes, Windows will re-install it if the device is not disabled, unless you run a driver cleaner to remove all the driver files for the device.
Unless you are expecting to hear sound through the HDMI cable connected to your television, then remove the video card sound drivers as they can cause performance and/or stability issues.