SetupDiag can help fix Windows 10 upgrade issues – here's how to use it.

[Windows Central]

Did an upgrade or update fail to install, and Windows 10 didn't show an error? Use the SetupDiag tool to find out the root of the cause.
Although Windows 10 usually provides an error code about an upgrade or update failure, sometimes, it won't show anything leaving you guessing the root of the problem, which can be very frustrating, especially if you're trying to install a new version of the OS.
However, Microsoft offers an optional tool, known as SetupDiag, which is available for free and designed to diagnose and determine the exact reason an update or upgrade failed to install.

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