KB4586786 – Windows 10 1903 & 1909 Security Update

Windows 10 receives a new cumulative update KB4586786 for devices running Windows 10 v1903 and v1909. This patch is a security update patch that carries some quality fixes and improvements to the device along with the OS Build 18362.1198 and 18363.1198. It improves security when using Microsoft Office products and some Windows basic operations.

You can download and install KB4586786 either through the Windows Settings or via the Update Catalog. Now let’s explore the key changes in detail –

KB4586786 – Windows 10 1903 & 1909 Security Update

KB4586786 Changelog for 19H1 and 19H2

Here are the key changes –

KB4586786 – Windows 10 1903 & 1909 Security Update.

Windows 10, 1909

The key changes of this security update are –

  • In this update, all the improvements for Windows 10, v1903 added by Microsoft.
  • There is no other issue that has been recorded for this release.

Windows 10, 1903

The key changes of this security update are –

  • The company has updated the 2020 DST start date for the Fiji Islands to December 20, 2020. 
  • Windows 10 team has worked on an issue with the package frame launcher (PSF) that passes a malformed parameter to a shim. 
  • Microsoft has improved the security updates for the following:

Microsoft Scripting Engine, the Microsoft Graphics Component, Windows Input and Composition, the Windows Wallet Service, Windows Fundamentals, and the Windows Kernel.

KB4586786 Known issues

The issue with this update is:

Issue: 1

When you try to update your device from Windows 10, version 1809, or later, then your system or user certificates might be lost.


In order to resolve this issue, you can uninstall your window by going back to your previous version of Windows. You can open the recovery page for better understanding. 

Microsoft is working on a resolution and will provide updated bundles and refreshed media in the upcoming update.

Download and Install KB4586786 on Windows 10 19H2 & 19H1

Before you proceed, make sure you have installed the latest SSU KB4586863. You can use three methods to get the patch update on your Windows 10 device. Here are the followings:

1] Through Windows update

To download the update through Windows update, use the steps –

  • Right-click on Start and select Settings.
  • Then select Update & Security > Windows Updates.
  • On the right side, click the Check for updates button.
  • Wait for a while until it starts scanning and downloading the update.
  • Once it downloads KB4586786, click on the Install now button to install it.

2] Through Microsoft update catalog

You can also get the update through the Microsoft update catalog. Here are the steps:

  • Navigate to the Microsoft Update Catalog page. 
  • Download and run the standalone package that came along with this release.
  • Then double click on .MSU File to install the update.

3] Windows Server Update Services (WSUS)

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

  • Product: Windows 10 version 1903 and 1909.
  • Classification: Security Updates