Preinstalled system applications and the Start menu may not work on some computers when you upgrade from Windows 8 to Windows 10 Version 1511.
This issue occurs because of a race condition that causes certain registry keys to become inaccessible to logged-in users. Therefore, the preinstalled system applications that have to touch those registry keys can't be installed during the appx deployment phase.
How to get this update
Method 1: Windows UpdateThis update will be downloaded and installed automatically.
Method 2: Microsoft Update CatalogTo get the stand-alone package for this update, go to the Microsoft Update Catalog website.
PrerequisitesThere are no prerequisites for installing this update.
Registry informationTo apply this update, you do not have to make any changes to the registry.
Restart informationYou may be prompted to restart the computer after you apply this update.
Update replacement informationThis update doesn't replace a previously released update.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.