ok, as promised, a guide to setting up hardware profiles:
for this example i will show how to have onboard audio working and USB audio disabled in one profile,
and Onboard audio disabled and USB audio working in a second profile.
Start by going to your control panel and selecting system:
Next select the hardware tab, and click "Hardware Profiles"
Copy your current profile and name it something relevent
Now select the new profile and click properties, on there click "This is a portable computer, and dock state unknown"
Also select "Always include this profile as an option when windows starts"
Once done click ok, and ok, now you should be back here:
Click device manager and locate your USB audio device, and select properties,
Now in the drop down box at the bottom select "Disable in this profile"
Now restart and load the second profile you created for the USB audio device, load device manager and select the onboard audio device, and disable on this profile again, but enable the USB audio device on this profile.
Job done