If you are seeing this error during an OS upgrade from within Windows, bypass the running OS entirely by booting directly into Windows Preinstallation Environment (WinPE) or Windows Recovery Environment (WinRE).

: Use the official Microsoft Media Creation Tool rather than third-party ISO sites.

Could Not Load Required File Winsetup Dll 0xc1 Verified __top__

If you are seeing this error during an OS upgrade from within Windows, bypass the running OS entirely by booting directly into Windows Preinstallation Environment (WinPE) or Windows Recovery Environment (WinRE).

: Use the official Microsoft Media Creation Tool rather than third-party ISO sites.