September 14, 2021—KB5005566 (OS Build 18363.1801)

EXPIRATION NOTICEAs of 9/12/2023, KB5005566 is only available from Windows Update. This update is no longer available from the Microsoft Update Catalog, or other release channels. We recommend that you update your devices to the latest security quality update.

8/24/2021 **IMPORTANT **Starting in October 2021, there will no longer be optional, non-security releases (known as “C” releases) for Windows 10, version 1909. Only cumulative monthly security updates (known as the “B” or Update Tuesday release) will continue for Windows 10, version 1909.

11/19/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. To view other notes and messages, see the Windows 10, version 1909 update history home page.NoteFollow @WindowsUpdate to find out when new content is published to the release information dashboard.

Highlights

• Updates security for your Windows operating system.

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Addresses an issue that causes PowerShell to create an infinite number of child directories. This issue occurs when you use the PowerShell Move-Item command to move a directory to one of its children. As a result, the volume fills up and the system stops responding.
  If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device. For more information about the resolved security vulnerabilities, please refer to the new Security Update Guide website.

Windows Update ImprovementsMicrosoft has released an update directly to the Windows Update client to improve reliability. Any device running Windows 10 configured to receive updates automatically from Windows Update, including Enterprise and Pro editions, will be offered the latest Windows 10 feature update based on device compatibility and Windows Update for Business deferral policy. This doesn’t apply to long-term servicing editions.

Windows 10 servicing stack update - 18363.1790

• This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Known issues in this update

How to get this update

If you want to remove the LCUTo remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command:DISM /online /get-packages.Running Windows Update Standalone Installer (wusa.exe) with the**/uninstall **switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File informationFor a list of the files that are provided in this update, download the file information for cumulative update 5005566. For a list of the files that are provided in the servicing stack update, download the file information for the SSU - version 18363.1790.