Hi LISON Marie-France,
Thanks for your reply.
To be honest, there are many reasons why we fail to install the feature update. What is the windows version of the client? 2004 or 1909. Have you install the latest SSUs and CUs. If not, I recommended to install the latest SSUs and CUs first. And then, we could try to install the feature update for Windows 10 20h2.
In addition, the Windows Update assistant maybe help if you want to upgrade to the latest Windows version. Please refer to the below link to download the Windows Update Assistant:
https://support.microsoft.com/en-us/topic/windows-10-update-assistant-3550dfb2-a015-7765-12ea-fba2ac36fb3f
Of course, we could do more research if you want to upgrade by WSUS or SCCM or other methods. Please help to provide the error information of the windowsupdate.log and CBS.log.
Thanks for your time.
Regards,
Rita
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