Windows 11 Audio Not Working After KB5129195? Fix It

 

If your Windows 11 PC suddenly went silent — no sound from speakers, headphones, or Bluetooth — and it started right after a Windows update in mid-September 2026, you are not imagining it. Microsoft has confirmed that its emergency update KB5129195 breaks audio on some PCs. The good news: the bug is acknowledged, a permanent fix is expected at the October 2026 Patch Tuesday (13 October), and there are proven workarounds you can apply today.

This guide explains what happened and walks you through every fix, from the quickest check to the reliable rollback.

What Is KB5129195 and Why Did It Break Audio?

On 8 September 2026, Microsoft released the September Patch Tuesday update (KB5124008). It caused new problems of its own: Remote Desktop connections would fail after a few minutes, and host folder sharing stopped working in Linux virtual machines used by apps such as Claude Cowork and the Windows Subsystem for Linux.

Six days later, on 14 September 2026, Microsoft pushed an emergency out-of-band update — KB5129195 — to clean up that mess. It fixed the RDP and shared-folder issues, but introduced fresh ones:

• Broken audio on some PCs. Microsoft has acknowledged that KB5129195 still breaks audio, and the proper fix may not arrive until the October Patch Tuesday, scheduled for 13 October 2026.
• Affected builds: Windows 11 25H2 (Build 26200.9457) and 24H2 (Build 26100.9457), both shipped via KB5129195.
• Related reported issues include Code 10 ("This device can't start") errors on audio devices in Device Manager, domain-joined PCs losing their secure trust relationship, and AMD Radeon GPU driver timeouts, black screens, and freezes.

In other words, the patch that was meant to fix the September update's problems became the source of a new one. As we covered in our Pixel keyboard fix from this month's October update, it is not uncommon for a single update to fix one thing while breaking another — which is why confirming the exact update is always the first step.

Step 0: Confirm the Update Is Really the Cause

Before changing anything, check that KB5129195 is actually installed on your PC:

1. Press Windows key + R, type winver, and press Enter. Confirm you see 24H2 or 25H2.
2. Open Settings > System > About and check the build number: 26100.9457 (24H2) or 26200.9457 (25H2).
3. Open Device Manager (right-click Start > Device Manager), expand Sound, video and game controllers, and look for a yellow warning icon or a Code 10 error on your audio device.
4. Go to Settings > Windows Update > Update history and look for KB5129195.

If everything matches and the sound died right after the update, you have your culprit. If the update is not there, you likely have a different audio problem — skip to the driver step anyway, as it fixes most generic cases too.

How to Fix No Audio After KB5129195: Step by Step

Work through these in order. Most users get sound back within the first three steps.

Step 1: Run the Built-in Audio Troubleshooter

Windows has a troubleshooter that resets the audio pipeline automatically:

1. Open Settings > System > Sound.
2. Scroll to the Troubleshoot section and run the Output device troubleshooter (on some builds this is under Settings > System > Troubleshoot > Other troubleshooters > Audio).
3. Follow the prompts and apply any suggested fix, then test your audio.

This resolves the issue when the update only misconfigured the output device rather than the driver itself.

Step 2: Reinstall the Audio Driver

If the troubleshooter finds nothing, a corrupted or incompatible audio driver is the most common cause:

1. Right-click Start and open Device Manager.
2. Expand Sound, video and game controllers.
3. Right-click your audio device (e.g. Realtek, Intel Smart Sound) and select Uninstall device. Do not tick "Delete the driver software" unless you have the correct driver installer saved.
4. Restart your PC. Windows will reinstall a working driver automatically on boot.
5. Test the audio. If it works but sounds wrong, visit your PC or motherboard maker's support page and install the latest audio driver for your model.

This is the step that fixes the majority of Code 10 audio errors reported after this update.

Step 3: Check the Default Playback Device

After an update, Windows sometimes switches output to the wrong device (for example a monitor instead of your speakers):

1. Right-click the speaker icon in the taskbar and open Sound settings.
2. Under Choose your output device, select the correct speakers or headphones.
3. Run the Test under Format to confirm sound is flowing.

Step 4: Roll Back KB5129195

If the audio broke the same day the update installed and the steps above did not help, removing the offending update is the most reliable fix:

1. Open Settings > Windows Update > Update history > Uninstall updates.
2. Find KB5129195 (dated mid-September 2026) and select Uninstall.
3. Restart when prompted, then test your audio.

One caution: cumulative updates include security fixes, so rolling back leaves your PC without them until you reinstall a patched version. Because Microsoft has said a proper fix is expected on 13 October 2026, treat the rollback as temporary and plan to install the October Patch Tuesday update the day it arrives.

Step 5: Use System Restore

If the update does not appear in the uninstall list:

1. Press Windows key + R, type rstrui, and press Enter.
2. Pick a restore point dated before 14 September 2026.
3. Follow the wizard and let the PC restart.

Your files are preserved, but applications installed after that date will need reinstalling.

Step 6: Install the October 2026 Patch Tuesday Update

Once 13 October 2026 arrives, do this regardless of whether sound is already back:

1. Open Settings > Windows Update and click Check for updates.
2. Install the October cumulative update and restart.
3. Confirm your audio still works afterwards.

This is the permanent fix Microsoft is targeting, and it also restores the security patches lost by any rollback.

What NOT to Do

• Do not permanently disable your audio device or service to silence error messages — it masks the problem.
• Do not install "driver updater" tools from unfamiliar websites; get drivers only from your PC maker's site.
• Do not edit the registry based on random forum snippets. Nothing in this fix requires it.

Frequently Asked Questions

Why is there no sound after the Windows 11 September 2026 update?

The emergency update KB5129195 (14 September 2026), which Microsoft released to fix Remote Desktop and Linux VM folder-sharing problems, breaks audio drivers on some PCs running Windows 11 24H2 (Build 26100.9457) or 25H2 (Build 26200.9457). Microsoft has acknowledged the issue and plans a proper fix for the 13 October 2026 Patch Tuesday.

How do I know if KB5129195 caused my audio problem?

Check your build number (Settings > System > About) and your update history (Settings > Windows Update > Update history). If you have build 26100.9457 or 26200.9457, KB5129195 is installed, and the audio stopped working around mid-September 2026, the update is almost certainly the cause.

Should I uninstall KB5129195 to fix the audio?

Yes, if the driver reinstall and troubleshooter did not work. Removing the update restores sound for most affected users. Just remember it is a temporary workaround — reinstall the October Patch Tuesday update when it arrives so you do not miss security fixes.

Will Microsoft fix the KB5129195 audio bug automatically?

Microsoft has acknowledged the audio breakage and indicated a fix should arrive with the October 2026 Patch Tuesday on 13 October. Keep Windows Update enabled and check for updates on that date to receive it.

Conclusion

The KB5129195 audio bug is one of those cases where the repair patch itself became the problem — but unlike some update bugs, this one is confirmed by Microsoft with a real fix on the way. Run the troubleshooter, reinstall your audio driver, and if all else fails, roll back the update and grab the October 13 patch when it lands. Your speakers should be back in business.