Session Windowsupdatetracelog Failed: To Start With The Following Error 0xc0000035 Repack

This error message typically appears in the Windows Event Viewer

when a background diagnostic logging session fails to initialize. In most cases, it is a benign system glitch that can be safely ignored unless you are experiencing severe performance issues or blue screens. Microsoft Learn What the Error Means 0xc0000035 : This code usually refers to STATUS_OBJECT_NAME_COLLISION

, meaning a logging session with that exact name was already running or a file with that name already exists. WindowsUpdateTraceLog

: This is a specific event tracing session used by the operating system to track the health and activity of the Windows Update service. Benign Nature : Experts from Microsoft Community Support

often note that these log entries are common during normal operations and do not necessarily indicate a critical system failure. Microsoft Learn How to Fix It

If you notice system slowdowns or want to clear the error, try these steps: Troubleshoot problems updating Windows - Microsoft Support

The error code 0xC0000035 is formally defined as STATUS_OBJECT_NAME_COLLISION, which indicates that a logging session or file name that Windows tried to create already exists. In the context of WindowsUpdateTracelog (or related logs like RUXIMLog), this usually occurs during a system restart when Windows attempts to start a diagnostic trace that didn't shut down or clean up properly in the previous session.

If your computer is otherwise updating and running normally, this error can typically be safely ignored. However, if you want to resolve it or are experiencing update issues, follow these steps: 1. Run Built-in Repair Tools

Use the Windows Update Troubleshooter to automatically identify and fix common configuration errors.

Go to Settings > System > Troubleshoot > Other troubleshooters. Select Windows Update and click Run. 2. Repair System Files

Corrupted system files can cause naming collisions in the kernel event tracing system. Use the following commands to repair them: Open Command Prompt as an Administrator.

Run the Deployment Image Servicing and Management (DISM) tool:DISM /Online /Cleanup-Image /RestoreHealth

Once finished, run the System File Checker (SFC):sfc /scannow 3. Clear Windows Update Cache

Deleting the temporary update files can resolve conflicts where the system tries to restart a trace based on outdated data. Open Command Prompt as Administrator. Stop the Update service: net stop wuauserv This error message typically appears in the Windows

Navigate to C:\Windows\SoftwareDistribution and delete all contents. Restart the service: net start wuauserv 4. Advanced: Registry Modification

If the error persists and floods your Event Viewer, you can disable the specific autologger that is failing:

Open Registry Editor (regedit) and navigate to:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WMI\Autologger\EventLog-System

Look for the subkey associated with the trace log (often a GUID like b675ec37-...). Change the Enabled and EnableProperty values from 1 to 0.

Warning: Back up your registry before making manual changes. Kernel-EventTracing - Microsoft Q&A

The error 0xC0000035 (technically STATUS_OBJECT_NAME_COLLISION) is a common "benign" error in the Windows Event Viewer. It typically occurs when a system component, like WindowsUpdateTracelog, tries to start a logging session that is already active or hasn't been properly closed from a previous run.

If your computer is otherwise running smoothly, this error can often be safely ignored. However, if you are experiencing performance lags or update issues, here are the steps to resolve it: 1. Basic Troubleshooting

Run Windows Update Troubleshooter: This built-in tool can reset common update components automatically. Find it in Settings > Update & Security > Troubleshoot > Additional troubleshooters.

Perform a System Scan: Use the System File Checker (SFC) and DISM tools to repair corrupted system files that might be causing the logging conflict. Open Command Prompt as Administrator. Run sfc /scannow. Run DISM /Online /Cleanup-Image /RestoreHealth. 2. Manual Reset of ETW Sessions

Since the error code indicates a "name collision," stopping the active session manually can clear the block.

Open Command Prompt (Admin) and type: logman query to list active sessions. Find the session named WindowsUpdateTracelog (or similar).

Stop it by typing: logman stop "WindowsUpdateTracelog" -ets. 3. Clear the Windows Update Cache

Corrupted temporary files in the update folder can trigger persistent logging errors. What Was Really Happening The error 0xc0000035 means:

Open Services (services.msc) and Stop the "Windows Update" service.

Navigate to C:\Windows\SoftwareDistribution and delete everything inside. Go back to Services and Start the "Windows Update" service. 4. Advanced Registry Fix

For persistent errors, you can modify the "Autologger" registry to prevent the session from conflicting on startup.

Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WMI\Autologger\WindowsUpdateTracelog

Find the Enabled and EnabledProperty keys and set their values to 0. Note: Always back up your registry before making changes.

Is your computer experiencing any specific slowdowns or failed updates alongside this error? Startup Error in Event Viewer - Microsoft Q&A

The error code 0xc0000035 is technically defined as STATUS_OBJECT_NAME_COLLISION, which indicates that a tracking session or logger is attempting to start using a name that is already in use by the system. In the context of "WindowsUpdateTracelog," this often occurs during routine background maintenance or updates and is generally considered benign unless you are experiencing active system instability or update failures. Understanding the Error

When Windows Update or performance diagnostic tools attempt to initiate a Kernel Event Tracing session, they may encounter this collision if a previous session didn't close properly or if multiple services are requesting the same log name simultaneously. Recommended Solutions

If this error is cluttering your Event Viewer or causing noticeable performance dips, you can resolve it through several standard Windows repair methods:

Run Built-in Troubleshooters: The first step should be the Windows Update Troubleshooter, which can automatically detect and clear common logging collisions.

Repair System Files: Use the System File Checker (SFC) and Deployment Image Servicing and Management (DISM) tools to repair corrupted registry keys or system files that might be triggering the collision: Open Command Prompt as an Administrator. Run sfc /scannow.

Once complete, run DISM /Online /Cleanup-Image /RestoreHealth.

Reset Update Cache: If the collision persists, clearing the update cache can force a "clean" restart of the logging session. This is done by stopping the Windows Update service and clearing the C:\Windows\SoftwareDistribution folder. On a clean boot

Registry Modification (Advanced): Some users resolve the persistent trace log error by navigating to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WMI\AutoLogger\EventLog-System and setting the Enabled and EnableProperty values to 0. Note: Always back up your registry before making changes.

If your system is otherwise stable and updates are installing successfully, many Microsoft Community Experts suggest that this specific log error can be safely ignored.

Are you experiencing any specific performance issues like slow boot times or failed updates alongside this error?

Here’s a detailed guide to understanding and resolving the error: “Session WindowsUpdateTraceLog failed to start with the following error 0xc0000035 repack”.

This error typically appears in Windows Event Viewer or during system repairs (e.g., using DISM or SFC), especially after a Windows update fails or a system image corruption occurs. The error code 0xc0000035 means STATUS_OBJECT_NAME_COLLISION – essentially, a duplicate object name exists (e.g., two processes trying to use the same log session name).

What Was Really Happening

The error 0xc0000035 means:

STATUS_OBJECT_NAME_COLLISION – “A file or folder with that name already exists.”

In simple terms:
Windows was trying to create a new Event Tracing for Windows (ETW) session named WindowsUpdateTraceLog.
But a session with that exact name was already running – probably leftover from a previous, incomplete Windows Update operation.

The word "Repack" in the message refers to Windows trying to reuse or repackage the logging session, but failing because of the name clash.

So, Windows Update couldn’t properly log what it was doing – which meant updates might still work, but diagnosing problems would be harder.

A. Duplicate ETW Session Registration

When repacking, you might have:

On a clean boot, Windows attempts to start WindowsUpdateTraceLog but finds that another session (or a stale handle) is already using its GUID or name.

Conclusion

Error 0xc0000035 for WindowsUpdateTraceLog signals a name collision—commonly a stale or duplicate ETW session. Resolution focuses on identifying and removing the conflicting session or registry entries, restarting services (or the system), repairing system components, and capturing diagnostics if the cause remains unclear.