"Alan Whitaker" <alan.whitaker@blueyonder.co.uk> wrote in message
news:F439D868-8CA5-4CEC-9855-6B49D47E935F@microsoft.com...[color=blue]
>I have the same problem on my Sony VGN-SZ4XWN. The only way I could get
>round the problem was in Device Manager in System in Control Panel. I
>found the uadio device and updated the driver the generic Micrsoft driver
>and got sound back again. I then received an update to the Sigma Tel High
>Definition Audio CODEC which was supposed to specifically address the
>problem of loss of sound on upgrading to Vista Ultimate, but alas still no
>sound so back to the generic driver.
> "chtaplin********.com" <chtaplin********.com@discussions.microsoft.com>
> wrote in message
> news:9877BF4C-51C2-4661-8668-286EB5CB6551@microsoft.com...[color=green]
>> Hi,
>>
>> I've read with great interests what has been posted here as I am
>> experiencing the same problems on my laptop (SONY VGN-FE41Z).
>>
>> Despite installing the latest driver downloaded form the Sony web site, I
>> still get a "NO AUDIO DEVICE INSTALLED" message.
>>
>> Could anyone give me a hand please?
>>
>> Many thanks
>>[/color]
>[/color]


you have to completely remove any vestige of the old driver before
reinstalling the audio driver when upgrading to Ultimate. There was a
bulletin detailing this on (what used to be) the sigmatel site - Google is
your friend.