I have a Sony laptop type - VGN-SZ491N - and I just upgraded from Windows Vista Business to Windows Vista Ultimate 32bit.
I have no audio on the laptop now. Down by the speaker icon in the lower right corner there is an X on the speaker, with the information: No audio output device installed.
Can anyone advise me on how to re-install the missing device
when I look in the - control panel/system/device manager/sound video and game controllers - I can se a - SigmaTel High Definition Audio CODEC - driver, which according to the properties information, is working properly.