If your system cannot "see" the update servers, the trace log will show the specific URLs being requested and the resulting HTTP status codes. This is invaluable for identifying if a firewall, proxy, or ISP is blocking the connection. 2. Resolving WSUS Discrepancies
When Windows Update fails, the standard error codes (like 0x80070005 or 0x8024402F ) are often vague. To truly understand what is happening under the hood, Windows administrators and power users rely on .
For system architects, the logman utility allows you to query the status of the WindowsUpdate_trace_log directly from the command line. By running logman query "WindowsUpdate_trace_log" -ets , you can see the buffer size, the number of buffers written, and the exact file path where the real-time data is being cached. windowsupdate_trace_log
Warning: This file can get very large. Remember to delete the Flags and Level registry keys when you are done troubleshooting, or system performance may suffer.
[TRACE] User attempting to close trace log. Log handle: 0x1A4F. Override: Log cannot be closed. Reason: Log is not a log anymore. Log is a mirror. If your system cannot "see" the update servers,
Windows will then collect all .etl files from the trace log directory, download the necessary symbols from Microsoft's symbol server, and compile them into a static WindowsUpdate.log file on your desktop. Anatomy of a Trace Log Entry
[WARNING] SYSTEM CLOCK DRIFT DETECTED. Local time 03:13. Network time 03:13. No drift. ERROR: Drift is internal. Resolving WSUS Discrepancies When Windows Update fails, the
Historically, Windows stored update information in a readable text file located at C:\Windows\WindowsUpdate.log. However, starting with Windows 10, Microsoft transitioned to Event Tracing for Windows (ETW). The WindowsUpdate_trace_log is an ETW session that captures real-time events from various update providers.
[TRACE] 2020-03-15: Update failed. Error 0x80070422. Underlying cause: User disabled Windows Update service. Registry key: "DisableWindowsUpdateAccess = 1". User note (etched into registry comment field): "You are not my real dad."