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We cannot see the Wuahandler.log.
Based on the information provided in the context, error code 0x8000FFFF is a generic error that can occur during Windows Update. Error code 0x87D00664 indicates that the update failed to install due to a network error. Since you have already tried several troubleshooting steps, it is possible that the issue is related to network connectivity or a problem with the update source. You can try the following steps:
Check your network connectivity and make sure that you have a stable internet connection.
Run the Windows Update troubleshooter to detect and fix any issues automatically.
Check if there are any pending updates that need to be installed before you can install the feature update.
Try downloading the update manually from the Microsoft Update Catalog and install it.
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