Microsoft released a new cumulative update ( KB5004296 ) for Windows 10 version 21H1 , Windows 10 version 20H2 , and Windows 10 version 2004 . As this came as an optional update, it won't be downloaded automatically. You will have to manually click on the " Download and Install " link from the Windows Update settings page.   The latest cumulative update (KB5004296) build includes performance improvements and bug fixes for Microsoft Windows 10. For a detailed list of improvements, and the offline installer, continue reading below.