Windows 11 users are reporting frustrating DAC (Digital-to-Analog Converter) errors with Code 10 after installing recent Microsoft updates KB5050021 and KB5050009. This issue prevents external USB audio devices from functioning properly, displaying the dreaded "This device cannot start" message in Device Manager.

Understanding the Windows 11 DAC Code 10 Error

The Code 10 error ("This device cannot start") typically appears when Windows fails to initialize a hardware device. In this case, the problem specifically affects USB-connected DACs and audio interfaces after installing:
- KB5050021 (January 2024 cumulative update)
- KB5050009 (Optional preview update)

Affected users report:
- Sudden loss of audio output through external DACs
- Device Manager showing yellow exclamation marks
- Error messages when trying to update drivers
- Audio reverting to built-in sound cards

Confirmed Workarounds and Fixes

1. Roll Back Problematic Updates

  1. Open Settings > Windows Update > Update history
  2. Click "Uninstall updates"
  3. Locate KB5050021 or KB5050009
  4. Select and uninstall
  5. Restart your PC

2. Manual Driver Reinstallation

  1. Right-click Start > Device Manager
  2. Expand "Sound, video and game controllers"
  3. Right-click your DAC > Uninstall device
  4. Check "Attempt to remove the driver" > Uninstall
  5. Disconnect the DAC
  6. Restart your PC
  7. Reconnect the DAC to trigger fresh driver installation

3. Disable USB Selective Suspend

  1. Open Control Panel > Power Options
  2. Click "Change plan settings" for your active plan
  3. Select "Change advanced power settings"
  4. Expand USB settings > USB selective suspend
  5. Set to "Disabled"
  6. Apply changes and restart

Microsoft's Response and Future Fixes

Microsoft has acknowledged the issue in their support forums, stating they're investigating reports of USB audio devices failing after recent updates. While no official patch has been released yet, the company suggests:

  • Checking for new driver updates from your DAC manufacturer
  • Using the Windows Update Troubleshooter
  • Waiting for future cumulative updates that may address the conflict

Preventing Future Audio Issues

To minimize update-related problems:

  • Create system restore points before installing major updates
  • Consider pausing updates if you rely on critical audio equipment
  • Maintain updated drivers from your hardware manufacturer
  • Use Windows' "Show or hide updates" tool to block problematic patches

Technical Analysis of the Conflict

Early investigations suggest the updates may be causing:

  • Conflicts with USB audio class drivers
  • Power management issues with USB controllers
  • Permission problems with audio endpoint devices

Advanced users can check Event Viewer for related errors under:
- Windows Logs > System
- Look for Event ID 219 from source "DriverFrameworks-UserMode"

Alternative Solutions

If the above fixes don't work:

  1. Try different USB ports (preferably USB 2.0)
  2. Use a powered USB hub
  3. Test the DAC on another computer
  4. Check for firmware updates from your DAC manufacturer
  5. Temporarily use a different audio output

Community Reports and Patterns

User reports indicate the issue primarily affects:

  • High-end USB DACs (Schiit, AudioQuest, etc.)
  • Professional audio interfaces
  • USB-C connected audio devices
  • Systems that recently upgraded from Windows 10

When to Contact Support

Consider reaching out to:

  • Your DAC manufacturer if issues persist
  • Microsoft Support if the problem affects multiple devices
  • A professional technician if you suspect hardware damage

Stay tuned for updates as Microsoft works on an official solution to this Windows 11 audio disruption.