UPDATE: Audio issues in Windows 10 Technical Preview Build 9879

Hello Insiders!

We received a lot of great feedback concerning audio problems with build 9860. We have been working to understand and resolve these problems, and I wanted to provide you with an update on two of them for Build 9879.

With the first problem audio would stop working, however everything looked fine with the system. If you investigated further you would find that the audio meters in the volume control would not move even when audio was playing, and the Windows Audio service (audiosrv) had stopped and needed to be restarted. We believe we’ve fixed this problem in Build 9879.

The second problem seemed similar in that no sound could be heard, however in this case the audio meters would move when sound was played and the Windows Audio service was running correctly. In some variations of the bug audio would work from some outputs but not others (i.e. headphones would work but not speakers, or vice versa). In most cases this problem was fixed by downloading and reinstalling the audio drivers from your OEM’s web site. We believe we understand this problem, but we need to collect more data to fully solve it. If you experience this problem we would really appreciate your help. Here’s what you can do:

1. While you seeing the problem, run dxdiag.exe
2. If asked to check signatures click "Yes"
3. Click "Save all information" and name the output file “before.txt”.
4. Download and install the audio drivers from your OEM and confirm that the issue is resolved.
5. Create a second DxDiag.txt and name the output file “after.txt”.
6. Send both DxDiag files and a link to the new driver that you installed to "mediaq at Microsoft dot com".

The more examples we can find, the more complete our fix will be for this audio problem.

As always, we appreciate your help in making Windows a better product!

John W [MSFT]


Discussion Info

Last updated April 19, 2019 Views 94,887 Applies to:

* Please try a lower page number.

* Please enter only numbers.

* Please try a lower page number.

* Please enter only numbers.

Hi John. I submitted my similar problem to this discusion (starting next paragraph below) on 11/18 via the Windows 10 Feedback link. After sending, I discovered an updated Audio driver at HPs' website and installed it, but Device Manager shows no change in version. So, I uninstalled the driver and ran the updated one as Administrator. I then received the following notice - "A digitally signed driver is required. 64-bit High Definition Audio Function Driver. Windows blocked the installation of a digitally unsigned driver..." This explains why Device Manager initially showed no change in version. The updated driver is sp40170 available at this link - ftp://ftp.hp.com/pub/softpaq/

I ran "Troubleshoot audio playback", it made some changes, but no help. Should I send the DXDIAG log file to "mediaq at Microsoft dot com"? If so, should I include this complete discussion? See my Windows Feedback below as the two problems discussed were NOT an issue with Builds 9841 or 9860.

I just performed a clean reinstall of Build 9879 by starting over from Build 9841. I did this to confirm this serious bug. I have lost audio while playing Youtube and Vevo videos with IE11. This was not an issue with Builds 9860 or 9841. Device Manager shows Sound, Video and Game Controllers installed. I have Conexant High Definition SmartAudio 221, Driver Provider Conexant, Driver Date 3/4/2008, Driver Version, Driver Signer Microsoft Windows Hardware Compatibility Publisher. When I run DXDIAG from Admin Command Prompt, there is an "Error: - Problem getting extra sound info." I click OK and every Tab (System, Display, Sound 1, Sound 2 and Input) shows "no problems found". I can see the sound level bouncing up/down from Speakers (lower right), but no sound. Build is 64-bit. I have an HP Pavilion dv6700z, AMD 64-bit dual core that runs Windows 7 64-bit Ultimate perfectly.

P.S. to my post today (11/18) that starts as follows: "I just performed a clean reinstall of Build 9879 by starting over from Build 9841..."

The Youtube and Vevo video runs in sync with the music, but there is no sound.

I have also lost the ability to play music CDs. Windows Media Player loads and attempts to run, but it starts/stops nine times and defaults to the view with Resume and Go to Library. Resume just starts the cycle over again. Builds 9841 and 9860 played music CDs OK.

[edit - Had same problem with both Build 9879 installs - just forgot to mention]

Compared to my 64-bit Windows 7 installation (separate HDD), there is a missing driver under Sound, Video and Game Controllers. However, this was also missing in both previous Builds where Youtube/Vevo sound, video and music CDs played OK, so it may not be needed. Device Manager shows no device driver software is missing anywhere. The missing driver per my Windows 7 HDD for this notebook is the NVIDIA Virtual Audio Device (Wave Extensible) (WDM). The driver set is as follows: Under System32 - drmk.sys (Microsoft file ver. 6.1.7601.18276), ksthunk.sys (Microsoft file ver. 6.1.7600.16385), nvaudcap64v.dll (NVIDIA file ver., nvvad64v.sys (NVIDIA file ver., and portcls.sys (Microsoft file ver. 6.1.7601.18276). Under Syswow64 - nvaudcap32v.dll (NVIDIA file ver.

Hi OUGrad, and thanks for the detailed information.

A DxDiag would be helpful, thanks. To the best of your knowledge, are the current audio drivers on your system the same ones that worked correctly in 9841 and 9860? It would also be helpful if you could send me your C:\Windows\Inf\setupapi.dev.log.

One other thing - Do headphones work, or is all audio broken?

Thanks for your help!

John W [MSFT]

P.S. Let's not worry about the missing NVidia driver, that's related to audio from your HDMI-connected screen.

John W [MSFT]
Hi John. I sent what you requested to that e-mail you provided all above. Let me know if it fails to arrive with all three attachments.

I got it and replied, thanks for the data! Per my e-mail, you mention that audio doesn't work with youtube and vevo videos, does it work under any other circumstances?

John W [MSFT]

John W [MSFT]
- Just replied to your e-mail John.

I was a member of TechNet and had all the resources available to me. 

Now I have been evaluating Win10 thru all the previews on a number of PC's and also more than one installation on different hard drives.

Everything was going fine with B9841 and B9860. (Personally - I believe B9860) should be the final release.)

I have also experienced the loss of audio on B9879 on ONE of my pc's. But it stopped working after it had been working fine to play music using stereo mix for a few days.

Audio from the Mic as default device - and also thru Stereo mix could be heard from the speakers.

But no music would pass from WMP or Winamp to the speakers - or get transmitted in a chat room.

I also do music editing - and the music editor application's audio WAS passed thru stereo mix to the speakers and broadcast in a chat room. (The app is Magix Audio Lab by XARA)

All my hard drives have 64 Bit operating systems installed.

The PC with the audio issue is custom built with an ASUS M4A78 motherboard which has a VIA sound device which has served me well during Win8 Previews and Win8.1 right to RTM and still going strong on Win8.1.

I did all the obvious attempts to overcome the issue - by re-installing the correct driver sll over again - with no success. I even re-installed the B9841 from scratch and then did the update to B9879. Still no joy.

However - I fitted that same hard drive to another custom built PC which has an ASUS M4A785 motherboard, This chipset also has a VIA audio device.

After the standard automatic reconfiguration and 'getting things ready' I had a healthy system with

the audio working perfectly.

The M4A785 does normally use a different version of the VIA driver.

On examining the drivers on both PC's I immediately saw different results under the Events Tab in the driver properties.

I have taken screen shots of both systems audio device properties and can send them to complete a report on my findings.


NOTE: The M4A785 is the PC with no audio issues - in the first screen shot.

Two screen shots were necessary for the M4A78 - because I had to scroll down the events.

I can only assume at this stage that there are minor differences in the chipsets.

Thanks for the information! If I understand the sequence of events...

1. You installed on a machine with a M4A78 and audio did not work

2. You moved that hard drive to a M4A785-based machine and after PNP did it's thing, audio worked.

I'd love to get a closer look at the screen captures and any other data you have on the differences between these two machines. Also could you send me a DxDiag from either machine (the M4A785 might be easiest, since that's where the hard drive is now) so I can get a look at the driver information? You can e-mail me at "mediaq at Microsoft dot com".

Many thanks, I appreciate your help!

John W [MSFT]

John W [MSFT]

Hi John. It is no problem for me to move hard drives from one pc to another.

Each pc has racks that let me 'hot-swop' drives.

Will get busy and send DXDIAX screenshots off asap.

An additional bit of info is that the audio does not work on the M4A78 with both the general download of Win10 TP and Win10 TP Enterprise.

btw - I also have a way for you to view my desktop when I call up the displays. You call up a URL I supply to put in your browser. Then you could take all the screenshots yourself.

The application is one I use for demonstrating live tutorials and it enables voice and text to be used in a session.

my sound did die once,  (was ok again after reboot) i will capture all the information next time it happens, thanx for this thread

* Please try a lower page number.

* Please enter only numbers.

* Please try a lower page number.

* Please enter only numbers.