KB4550927 Windows 10 1709 16299.1806, KB4550939 1703 15063.2346

Patch Tuesday Security updates KB4550927 Windows 10 1709 16299.1806 and KB4550939 1703 15063.2346 Changelog.

KB4550927 for Windows 10 1709 16299.1806 Update Image 1

Another patch Tuesday is here and Microsoft has rolled out the quality in the form of KB4550927 is for Windows 10 1709 and KB4550939 for Windows 10 1703. Though no important features are being introduced in both the patches, some generic security improvements are introduced in order to better safeguard the system and to offer better performance.

The below section covers all the details of the packages including its changes, issues, and the ways to download it. The most popular method to install the package is through the automatic Windows update. However, the giant software also provides manual installation via Microsoft Update Catalog as well.

KB4550927 for Windows 10 1709 16299.1806

  1. The patch contains updates for enhancing security when Windows performs necessary functions.
  2. Enhancement in security for file storage and management.
  3. The patch also contains security improvements for
  4. Finally, it has security updates for various Microsoft products like “Windows Media, Microsoft Scripting Engine, Windows App Platform and Frameworks Windows Kernel, Microsoft Graphics Component, Windows Core Networking, Windows Storage and Filesystems, Windows Management, Windows Cloud Infrastructure, Windows Fundamentals, Windows Update Stack, and the Microsoft JET Database Engine”.

Known issues with KB4550927

KB4550927 has one known issue as described below:

Systems on a domain are found to be unable to carry out the installation of apps published using a Group Policy Object (GPO). The problem, however, only affects app installation methods that use .msi files. There’s no issue noticed with other means such as installing from the Microsoft Store.


Though no resolution is available at the moment, we may expect a fix in one of the upcoming updates. Meanwhile, as a workaround to this situation, try to manually install the app on the device.

How to get KB4550927 for Windows 10 version 1709

As with any other patches, there are three ways of getting the latest ones on your system. But before making an attempt to install the package, first, ensure to install the latest servicing stack update. This has benefits like enhancement in the reliability of the update procedure, reduces potential problems that might occur while applying Microsoft fixes.

By default, the system will automatically download and install any latest updates relevant available on the server. The system stops getting automatic updates if you have paused or temporarily stopped the process.

Find the standalone package in the Microsoft Update Catalog site and download the supportable architecture.

Users can manually fetch the patches to do so –

  1. Open Windows Settings using “Win+I” key combination.
  2. Choose Update & Security.
  3. Click Check for updates. Hit Download button and finally Restart Windows 10 PC to install them.

Source – Release Note

KB4550939 for Windows 10 1703 15063.2346

KB4550939 for Windows 10 1703 15063.2346 Image 2

Here is the list of changes and fixes that KB4550939 for Windows 10 has to offer –

  1. Include updates to enhance protection when Windows executes fundamental operations.
  2. Updates are also out to refine security when using Microsoft Office products.
  3. Microsoft deals with a problem that causes a memory leak in the LsaIso.exe process. It happens when the server is under a heavy authentication load and Credential Guard is turned on.
  4. KB4550939 focuses on an issue with running klist.exe. Basically, it causes lsass.exe to stop operating and generates an access violation error (0xC0000005).
  5. The patch also addresses a problem with merging Windows Defender Application Control policies. In certain situations, it generates a duplicate rule ID error and causes the Merge-CIPolicy PowerShell command to fail.
  6. Security updates to various platforms are out such as the “Microsoft Scripting Engine, Windows Kernel, Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Media, Windows Management, Windows Fundamentals, Windows Core Networking, Windows Update Stack, and the Microsoft JET Database Engine”.

Known Issues

Symptom 1

Certain devices that are on a domain might not be able to install applications published using a Group Policy Object (in short GPO). However, it only affects app installations that use .msi files. It does not affect any other installation procedures like the ones from Microsoft Store.


As a temporary workaround, try to manually install the app on the device.

Currently, Microsoft is yet to provide a resolution as the team is working on it and will soon release it in the forthcoming release.

How to Get KB4550939 for Windows 10 1703

Similar to other patches, KB4550939 can also be installed on devices using a few ways. However, before proceeding to grab the patch, ensure to install the latest servicing stack update (SSU). This is important to carry out as it enhances the reliability of the update procedure. Moreover, it also helps in reducing potential problems that might occur during LCU installation.

One of the ways to get KB4550939 is through Windows Update and to do so,

  1. Fire up Start Menu and click the cog icon.
  2. Choose Update & Security followed by a click on Check for Updates.

As an alternative, navigate Microsoft Update Catalog and grab the respective file.

Source – Release Note

That’s all!!!

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Topics:  Windows update

  1. Hello John, Did this patch fire the bug?

  2. John P. Sloane


    Would you please explain to me why is it that, every time Windows updates, it returns all my Settings, Defaults, etc. back to the Microsoft defaults? I always set my defaults, however, Windows updates totally ignore them.