After you apply update 2919355 on a Windows 8.1 Pro-based computer that is not domain-joined, you can customize the Start screen. By default, only domain-joined computers in Windows 8.1 Pro can customize the Start screen.
This issue occurs because update 2919355 applies a Start screen customization policy incorrectly to the Pro edition of Windows 8.1.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 3008289 - Last Review: Nov 18, 2014 - Revision: 1