Go to Dell's web site - this is a known problem with a solution.
http://www.dellcommunity.com/supportforums/ There are also other threads
here that address this.
"Per Nermo" <> wrote in message
news:AEF8E38D-D63B-446E-A570-...
>I was encouraged today bt WindowsUpdate to install (yesterday's) optional
>new version (from Sep 2007 ?) of the "IDT High Definition Audio CODEC"
>(driver), and having done so, after a system Restart, I got the message "No
>sound device installed" (and the loudspeaker icon was crossed out red in
>the System Tray).
>
> I then entered the CP - System - Device handler - Sound device - and
> 'rolled back' to the previous driver version, then OK'd and immediately my
> Sound Device was back again, fresh and sound (literally).
>
> How is it that we obviously can not trust Microsoft to provide fully
> tested software pushed by Windows Update ? What is MS intending to do to
> avoid problems like this ?
>
> OR: What did I do wrong to experience this ? Did I miss a warning that
> installing this update might remove my Sound Device ?
>
> Does there exist a means to "re-enable" the Sound Device with the updated
> driver version installed ?
>
> (I'm running Vista (Home Premium) SP 1 (installed on Apr 18 through
> WindowsUpdate) on a DELL 9400 Inspiron LapTop)
>
> regards,
> Per Nermo
> Oslo, Norway