Compatibility update for the web, store, and media upgrade experience is available for Windows 8.1 and Windows Server 2012 R2: December 2013

Update information

How to obtain this update

This compatibility update is offered when you upgrade to the release version of Windows 8.1 or Windows Server 2012 R2.

Upgrade actions

This compatibility update may trigger several actions when you upgrade to the latest version of Windows 8.1 or Windows Server 2012 R2. The following are the most common actions that may be triggered:

• Upgrade block
  
  Puts an upgrade block on an application that may cause the upgrade to Windows 8.1 or to Windows Server 2012 R2 to fail. Windows 8.1 and Windows Server 2012 R2 put an upgrade block on a third-party application only if the manufacturer is notified. The user must uninstall the application to continue with the upgrade.
• Hard block
  
  When a hard block is put on an incompatible application, you cannot run the application after you upgrade. Windows 8.1 and Windows Server 2012 R2 put a hard block on a third-party application only if the manufacturer is notified. Improves the user experience by warning the end-user and provides a "more information" URL about the product.
• Soft block
  
  A soft block notifies you when a primary function of an application may not work or may cause application instability. Improves user experience by warning the end-user and provides a "more information" URL about the product.
• Driver block
  
  May block an existing driver on your computer when you upgrade to Windows 8.1 or to Windows Server 2012 R2. If this occurs, a driver for Windows 8.1 and Windows Server 2012 R2 is installed.
• Block upgrade, can reinstall
  
  May block the upgrade to Windows 8.1 or Windows Server 2012 R2. To continue the upgrade, you must uninstall the application or driver. After Windows 8.1 or Windows Server 2012 R2 is installed, the application or driver may function correctly after it is reinstalled.
• Reinstall after upgrade
  
  Allows the upgrade to the release version of Windows 8.1 or Windows Server 2012 R2 to complete successfully. However, you can reinstall the application or device after the upgrade.
• Migration block
  
  This action blocks an incompatible application from being migrated either completely or partially during the upgrade from Windows 8 to Windows 8.1 so that the upgrade completes successfully.

Changes in upgrade behavior when you install the update

Applications or devices may experience a change in behavior after this compatibility update is installed.

The following table lists the applications and devices that may be dynamically migrated when you update. This table also describes the behavior of these applications and devices after this compatibility update is installed.

Update replacement information

This update replaces the following update:

2890141 Compatibility update for the web, store, and media upgrade experience is available for Windows 8.1 and Windows Server 2012 R2: November 2013

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Third-party information disclaimer

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.