IMPORTANT Windows 10, version 1809, will reach end of service on November 10, 2020 for devices running Windows 10 Home, Pro, Pro for Workstation, and IoT Core editions. These devices will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.
IMPORTANT Starting in July 2020, we will resume non-security releases for Windows 10 and Windows Server, version 1809 and later. There is no change to the cumulative monthly security updates (also referred to as the "B" release or Update Tuesday release). For more information, see the blog post Resuming optional Windows 10 and Windows Server non-security monthly updates.
IMPORTANT Starting in July 2020, all Windows Updates will disable the RemoteFX vGPU feature because of a security vulnerability. For more information about the vulnerability, see CVE-2020-1036 and KB4570006. After you install this update, attempts to start virtual machines (VM) that have RemoteFX vGPU enabled will fail, and messages such as the following will appear:
- “The virtual machine cannot be started because all the RemoteFX-capable GPUs are disabled in Hyper-V Manager.”
- “The virtual machine cannot be started because the server has insufficient GPU resources.”
If you re-enable RemoteFX vGPU, a message similar to the following will appear:
- "We no longer support the RemoteFX 3D video adapter. If you are still using this adapter, you may become vulnerable to security risk. Learn more (https://go.microsoft.com/fwlink/?linkid=2131976)”
IMPORTANT We have been evaluating the public health situation and understand the impact this is having on many of our customers. To help ease some of the burdens customers are facing, we are going to delay the scheduled end of service date for the Home, Pro, Pro Education, Pro for Workstations, and IoT Core editions of Windows 10, version 1809 to November 10, 2020. This means devices will receive monthly security updates only from May to November. The final security update for these editions of Windows 10, version 1809 will be released on November 10, 2020 instead of May 12, 2020.
- Updates an issue with the out of box user experience on some devices that prevents an upgrade from completing. This issue occurs because the device will not allow user input on the Microsoft Software License Terms page or the Cortana page.
Improvements and fixes
This non-security update includes quality improvements. Key changes include:
- Allows administrators to use a Group Policy to enable Save Target As for users in Microsoft Edge IE Mode.
- Addresses an issue with untrusted URL navigations from Internet Explorer 11 by opening them in Microsoft Defender Application Guard using Microsoft Edge.
- Addresses an issue that displays a black screen to Windows Virtual Desktop (WVD) users when they attempt to sign in.
- Addresses a reliability issue in the graphics kernel.
- Addresses an issue with the out of box user experience on some devices that prevents an upgrade from completing. This issue occurs because the device will not allow user input on the Microsoft Software License Terms page or the Cortana page.
- Addresses an issue that causes an application to stop responding temporarily, which causes extra z-order operations that affect the Window.Topmost property of a window.
- Addresses an issue with the CleanupProfiles Group Policy object (GPO). After you upgrade the operating system, when you configure the CleanupProfiles GPO, it fails to remove unused user profiles.
- Addresses an issue that fails to set the desktop wallpaper as configured by a GPO when you specify the local background as a solid color.
- Addresses an issue that prevents you from signing in on certain servers. This occurs when you enable a Group Policy that forces the start of a computer session to be interactive.
- Addresses an issue that occurs when you first sign in to an account or unlock an existing user session using Remote Desktop Services (RDS). If you enter an incorrect password, the current keyboard layout changes unexpectedly to the system default keyboard layout. This keyboard layout change might cause additional attempts to sign in to fail or lead to account lockouts in domains with low account lockout thresholds.
- Addresses stop error 0xC2 in usbccgp.sys.
- Addresses an issue that displays the incorrect CPU frequency for certain processors.
- Addresses an issue that randomly changes the time offset of the time format returned by the command WMIC.exe OS Get localdatetime/ value.
- Addresses an issue with Task Manager reports that show an incorrect cache value for the CPU.
- Addresses an issue that prevents Microsoft User Experience Virtualization (UE-V) from assigning the Microsoft Outlook Signatures.
- Addresses an issue that prevents the Smart Cards for Windows service from starting, which prevents the use of a smart card for authentication. The event log shows the error, “Server Control failed to access start event: 621”.
- Addresses an issue that causes Windows to stop working and generates error 0x17. This issue occurs when Windows Defender Device Guard is enabled, and a driver is loaded with a 4K Microsoft Portable Executable (PE) header.
- Adds a new Microsoft Event Tracing for Windows (ETW) provider named "Microsoft-Antimalware-UacScan". This ETW provider reports the details of the context for each User Account Control (UAC) request in the ETW provider manifest.
- Addresses an issue that causes stop error 0xd1 in msiscsi.sys. This issue occurs when moving certain arrays from one cluster node to another.
- Addresses an issue that prevents Windows Update and Microsoft Store from connecting to peers over virtual private networks (VPN) for downloads.
- Addresses an issue with support for On-Behalf-Of flows (OBO) when using the Microsoft Authentication Library (MSAL).
- Adds support for the Transport Layer Security (TLS) 1.1 and 1.2 protocols when connecting to SQL Server using the data providers in Microsoft Data Access Components (
- Addresses an issue with SQL Server that might cause performance issues if you configure a Linked Server provider to load out-of-process.
- Addresses an issue with cluster validation that incorrectly tests internal switches that are not being used in a cluster.
- Addresses an issue with deduplication that causes long wait times on Resilient File System (ReFS) Cluster Shared Volumes (CSV).
- Addresses an issue that might prevent some applications from behaving correctly. This occurs when you publish them as Remote Application Integrated Locally (RAIL) applications using RDS and change the docking for an AppBar window.
- Addresses an issue with a deadlock in the Transmission Control Protocol/Internet Protocol (TCPIP) driver that causes the operating system to stop working or stop responding.
- Addresses an issue that causes the Routing and Remote Access Service (RRAS) to stop responding for new connections. However, RRAS continues working for existing connections.
- Addresses an issue that causes the RRAS administrator Microsoft Management Console (MMC) to stop responding randomly when you are performing administrative tasks or at startup.
- Improves the Windows Server Storage Migration Service by:
- Adding inventory validation.
- Improving retransfer performance .
- Resolving multiple issues, including reliability issues.
- Verifying that source machines have installed the current update.
For more information, see Storage Migration Service October 2020 Update.
If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.
Windows Update Improvements
Microsoft 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.
Known issues in this update
|After installing KB4493509, devices with some Asian language packs installed may receive the error, "0x800f0982 - PSFX_E_MATCHING_COMPONENT_NOT_FOUND."|| |
Note If reinstalling the language pack does not mitigate the issue, reset your PC as follows:
Microsoft is working on a resolution and will provide an update in an upcoming release.
How to get this update
Before installing this update
Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
Install this update
|Release Channel||Available||Next Step|
|Windows Update or Microsoft Update||Yes||Go to Settings > Update & Security > Windows Update. In the Optional updates available area, you’ll find the link to download and install the update.|
|Microsoft Update Catalog||Yes||To get the standalone package for this update, go to the Microsoft Update Catalog website.|
|Windows Server Update Services (WSUS)||No|| |
You can import this update into WSUS manually. See the Microsoft Update Catalog for instructions.
For a list of the files that are provided in this update, download the file information for cumulative update 4580390.
Note Some files erroneously have “Not applicable” in the “File version” column of the CSV file. This might lead to false positives or false negatives when using some third-party scan detection tools to validate the build.