Stranglehold: Thanks, but I have tried that already also to no avail.
PC_eye:
This is the motherboard I have just bought. I will try and remove the drivers and install them again manually. If that fails, I will uninstall, and and run setup.exe manuallly. If that fails I'll have to ring Gigabyte tomorrow - damn call lines don't open weekends, when I have time to sort it out.
I would expect this recent motherboard to have decent on board audio, and being Gigabyte, also to be reliable.