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In order to check which log files to view to understand why the 21H2 feature update is failing to install, you can follow the troubleshooting checklist provided by Microsoft here. Specifically, the checklist recommends checking the following log files for errors or issues:
setuperr.log: This file is located in the
%windir%\Panther directory and contains information about errors that occurred during the installation process.
setupact.log: This file is also located in the
%windir%\Panther directory and contains information about the installation process, including successful operations and warnings.
Event Viewer: This tool can be accessed by typing "Event Viewer" in the Windows search bar. From there, you can navigate to the "Windows Logs" section and view the "Setup" and "System" logs for any errors or issues related to the installation process.
WindowsUpdate.log: This file can be found in the
%windir%\WindowsUpdate.log directory and contains information about Windows Update operations.
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