|Just for info, in BIOS it should go a bit like this:|
Most likely it is under "Integrated Peripherals".
It could be "Onboard Audio," "HD Audio," "AC97 Audio," "Audio",
"Mainboard Audio" or similar.
Select "Enable" with the arrow keys and press "Enter."
Select "Save & Exit Setup" with the arrow keys, then press "Enter."
If it is already Enabled then you just exit without saving.
See also my questions in post #8 above.
If it was OK before you updated the drivers you could either do a driver roll back, or System Restore to a date before the change was made.
Always pop back and let us know the outcome - thanks