I have an XPS 14 laptop which I bought a couple of months ago (June, 2013). It is running Windows 7 Home Premium. Last Tuesday (8/13), I installed the latest round of Windows Updates. Restarted my computer after installation. Everything seemed fine. However, the next day when I next booted my machine up, there was no sound. The sound icon was in the system tray, but had a red "X," and if I tried to open the sound controls, there were no options to do anything, just "no audio device is installed."
Thinking that there was some conflict or issue with one of the updates, I did a System Restore to before the updates were installed. When my computer booted up after the restore, my sound was back. I then tried re-installing the updates, a few at a time, restarting after each installation. After each installation and restart, I still had sound. I then shut down my computer. However, the next time I booted it up, the sound was gone again.
At this point, I downloaded the sound (RealTek audio) driver from Dell's website and reinstalled my sound driver. After the reinstallation, my sound was working again...UNTIL THE NEXT TIME I BOOTED MY MACHINE AFTER SHUTTING IT DOWN.
So...reinstalling the driver fixes the problem, but only temporarily, and at the next boot up, the driver seems to be missing/not used again (it seems like maybe Windows is using/trying to use the Intel driver instead, but that driver is for my HDMI port). I will also note that that first time I booted up (the day after initially installing the Windows Updates), I also got a dialogue box saying that the Dell Quickset program (which I believe is the "Dell Audio" controller) did not start/run properly (and, if I recall correctly, was running in compatibility mode?).
Has anyone else seen/heard of/encountered this problem? I contacted Dell using chat, and the technician told me that my reinstalling of the driver would fix the problem (although I'd already told him that I had done that and that it *hadn't* fixed it). The only other suggestions I was given from Dell were 1) to navigate to the Microsoft page for diagnosing audio playback problems (which doesn't find anything wrong), and 2) to create a new user account (which doesn't seem likely to help, given that the problem is occurring before I even log on as a user).