Vista - Upgrade from Vista Basic to Ultimate and now no sound

I just upgraded to Vista Ultimate and now I have no output device installed.
How do I get my sound back? Help!

Open device manager (Control Panel, Classic Menu, Device Manager).
Find Sound Video and Game Controllers and doubleclick the item.
Your audio device should be enlisted.
Should it be missing click "Action" , Scan for hardware changes.
Now the item is present.
If not turn computer FULLY off (no restart!) and turn on again.
Go to your audio device and double click it. Check General (if device is working
properly), and the Driver tab. Search for driver (follow instructions in the pop-up window).
If you cannot find a driver this way, go to your manufacturer's support site, look for
a driver and install it.
It is also possible that the device manager shows an unknown device (marked yellow)
It can be your audio device.