Servicing stack update for Windows Server 2012, Windows 8.1 and Windows Server 2012 R2: July 9, 2019

Applies to: Windows Server 2012Windows 8.1Windows Server 2012 R2


This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Key changes include:

  • Addresses an issue with a Secure Boot feature update that may cause BitLocker to go into recovery mode because of a race condition.

Microsoft strongly recommends you always install the latest servicing stack update (SSU) for your operating system before installing the latest monthly security update. Installing servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft security fixes.

How to get this update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, see Windows Update: FAQ.

Note: This update is also available through Windows Server Update Services (WSUS).

Method 2: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

More information


There are no prerequisites for installing this update.

Restart information

You don't have to restart your computer after you apply this update.

Update replacement information

For Windows Server 2012 and Windows Embedded 8 Standard, this update replaces the previously released update KB3173426.

For Windows 8.1 and Windows Server 2012 R2, this update replaces the previously released update KB3173424

File Information

File information
The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

Windows 10 file information


For more information about SSUs, see Servicing stack updates.
Learn about the terminology that Microsoft uses to describe software updates.