Use Fix problems using Windows Update to reinstall the current Windows 11 build and repair Windows components while preserving installed applications, personal files, and settings.
Repair Windows without a clean installation
Because Audiosrv and the separate COM+ Event System service both fail, while DISM and SFC report no corruption, this is broader than a missing headset endpoint or damaged Audiosrv.dll. A repair reinstall is the appropriate next nondestructive step:
- Back up important data and record the BitLocker recovery key, if device encryption is enabled.
- Keep the computer connected to power and the internet.
- Open Settings → System → Recovery.
- Under Fix problems using Windows Update, select Reinstall now.
- Approve the restart option and select OK.
- Let Windows download and reinstall the repair version, then restart.
- After sign-in, check:
-
services.msc→ COM+ Event System -
services.msc→ Windows Audio -
mmsys.cpl→ Playback
-
This reinstalls the same Windows version, repairs system files and components, and preserves apps, files, and settings.^1^
If Reinstall now is unavailable—commonly on devices whose updates are managed by an organization—perform an in-place upgrade from matching Windows installation media instead:
- Create Windows installation media matching the installed edition, language, and architecture.
- Sign in normally and connect the media.
- Open the drive in File Explorer and run
setup.exefrom inside Windows. Do not boot from the USB. - Select Change what to keep.
- Select Keep personal files and apps.
- Select Install.
That option explicitly retains personal data, applications, and settings.^2^
What the access-denied error indicates
0x80070005 means that an operation performed during service initialization was denied. Normal permissions on Audiosrv.dll and es.dll therefore do not eliminate permission-related causes. The denied object could instead be:
- another file or directory;
- a registry key;
- a service security descriptor;
- a COM/DCOM resource;
- a resource locked or filtered by security software.
Service startup involves the Service Control Manager starting the host process and waiting for the service to initialize. A failure inside that initialization can be returned as the service-start error even though the service account and primary DLL are correct.^3^
Do not apply broad registry, DCOM, or filesystem permission resets without identifying the denied object. Incorrect ACL changes can weaken security or create additional failures.
Identify the denied object before changing permissions
If a root cause is required before performing the repair, capture the failure with Process Monitor:
- Run Microsoft Sysinternals Process Monitor as administrator.
- Press Ctrl+E to stop capture and clear existing events.
- Add filters:
- Result
isACCESS DENIED → Include - optionally Process Name
issvchost.exe → Include
- Result
- Start capture with Ctrl+E.
- In an elevated terminal, reproduce the failure:
sc query EventSystem
sc start EventSystem
sc query Audiosrv
sc start Audiosrv
- Stop capture immediately.
- Examine access-denied operations at the exact service-start timestamps. Check the Path, Operation, Process, Detail, and Stack fields.
- Correct only an object whose denied access is directly associated with the failed initialization.
Microsoft’s Process Monitor guidance recommends elevated capture and filtering for Access Denied, while warning that not every denied operation is an actual failure—requests for excessive access are often rejected normally.^4^
Also export Event Viewer → Applications and Services Logs → Microsoft → Windows → Audio → Operational around the failure timestamp.^5^
Is KB5127936 responsible?
KB5127936 is the October 28, 2026 preview update corresponding to Windows 11 26H2 build 26300.9818.^6^
Microsoft’s 26H2 release-health page does not list KB5127936 as causing Audiosrv or COM+ Event System failures with 0x80070005.^7^ A documented USB Audio Class 1.0 problem can produce no output or unavailable Sound settings, but it is associated with the September update and commonly includes a Device Manager Code 10. Your device reports as working, and that issue does not account for both Audiosrv and EventSystem failing.^8^
Uninstalling KB5127936 without changing the symptom further weakens—but does not conclusively disprove—a connection. If the repair reinstall fails, preserve the Process Monitor trace and exported event logs and open a Microsoft support case rather than applying guessed service or registry ACLs.
References
- Fix issues by reinstalling the current version of Windows | Microsoft Support
- Reinstall Windows with the installation media | Microsoft Support
- Service Startup
- Troubleshoot Apps failing to start using Process Monitor
- How to collect Windows audio event logs
- October 28, 2026 — KB5127936 (OS Builds 26300.9818 and 26200.9818) Preview
- Windows 11, version 26H2 known issues and notifications
- October 13, 2026—KB5127648 (OS Builds 26300.9711, 26200.9711 and 26100.9711) | Microsoft Support