Windows 10 version 21H1: All the changes so far

Windows Update
Windows Update (Image credit: Windows Central)

Microsoft's next big Windows 10 feature update is on the way. Just like the Windows 10 October 2020 Update, this upcoming release will be delivered as a cumulative style update for those running the current latest version of Windows 10. This means the update won't take long to install, and isn't as big as normal Windows 10 feature updates.

This release doesn't have an official name yet, but we know it will ship as version 21H1. This update won't include any huge new changes or features, as it's designed to be minor and only focus in business critical additions. Microsoft is planning a bigger Windows 10 feature update for later this year, codenamed Sun Valley instead.

The most notable new changes are that the old Microsoft Edge is no longer present, as the new Microsoft Edge is now being preinstalled and set as default. Microsoft is also enabling PCs with multiple Windows Hello peripherals to set a default, useful for when you're docked to a larger display and using an external peripheral for bioauthentication.

Overall, 21H1 for Windows 10 is a minor update, featuring mostly fixes and not much else. We've highlighted the most notable features below.

OS Details

  • Public name: May 2021 Update
  • Codename: N/A
  • Version: 21H1
  • Build: 19043
  • Released: May 2021

Version 21H1 changelog

New features

  • Windows Hello multicamera support to set the default as the external camera when both external and internal Windows Hello cameras are present.
  • Windows Defender Application Guard performance improvements including optimizing document opening scenario times.
  • Windows Management Instrumentation (WMI) Group Policy Service (GPSVC) updating performance improvement to support remote work scenarios.
  • Removed the Microsoft Edge Legacy desktop application that is out of support and installs the new Microsoft Edge.

Fixes and other improvements

  • Fixed an issue with zoom that occurs when using Microsoft Edge IE Mode on devices that use multiple high-DPI monitors.
  • We enabled administrators to use a Group Policy to enable extended keyboard shortcuts, including Ctrl+S, for users in Microsoft Edge IE Mode.
  • Fixed an issue that prevents the icon for a Toast collection from appearing in the Action Center if the icon file's URI contains spaces.
  • Fixed an issue that makes high dynamic range (HDR) screens appear much darker than expected.
  • Fixed an issue that causes video playback to be out of sync in duplicate mode when you use multiple monitors.
  • Fixed an issue that might cause applications to stop working while you type Japanese characters using the Microsoft Japanese Input Method Editor (IME) in compatibility mode.
  • Fixed an issue that might cause a device to stop responding during hybrid shutdown.
  • Fixed an issue that prevents users from adjusting or turning off the touchpad because of administrative settings.
  • Fixed a window rendering issue that causes content in a window to flash frequently when FlipEx is used.
  • Fixed a window rendering issue that causes content in a window to flash frequently when multi-plane overlay (MPO) is used.
  • Fixed an issue with Japanese input that occurs after focus changes between boxes in Microsoft Edge.
  • Fixed an issue that displays nothing or shows "Computing Filters" indefinitely when you filter File Explorer search results.
  • Fixed an issue that makes the split layout unavailable for the touch keyboard when you rotate a device to portrait mode.
  • Windows will now inform users when a child account in the Family Safety plan has administrative privileges.
  • Fixed an issue that prevents you from closing Toast Notifications using the Close button on touchscreen devices.
  • Fixed an issue with a heap leak that might cause explorer.exe to consume high amounts of memory.
  • Updated the Volgograd, Russia time zone from UTC+4 to UTC+3.
  • Added a new time zone, UTC+2:00 Juba, for the Republic of South Sudan.
  • Fixed an issue with the Windows Event Log Forwarding client, which returns the first matching certificate without checking private key permissions. With this update, the Windows Event Log Forwarding client selects the client's certificate only if the Network Service has read permissions for the private key.
  • Fixed an issue that causes PowerShell-based monitors to stop working when you enable transcription on the systems.
  • We fixed an issue that stops BranchCache from working if you activate Windows using Cloud Solution Provider (CSP) license.
  • Fixed an issue that prevents Windows 10 Home edition devices from upgrading to the Windows 10 Pro Education edition using mobile device management (MDM) services such as Microsoft Intune.
  • Fixed an issue that prevents App-V applications from opening and generates error 0xc0000225.
  • Fixed an issue in which some machines enrolled with an MDM service fail to sync if the device manufacturer's name contains a reserved character.
  • Fixed an issue with using a configuration service provider (CSP) policy to configure a custom setting for Audit Other Logon/Logoff events. The custom setting fails to take effect.
  • Fixed an issue that causes a system to stop working when no Trusted Platform Module (TPM) is present in the system. The error code in TpmTasks.dll!TrackTPMStateChanges is c0000005.
  • Fixed an issue that causes multiple instances of explorer.exe to run on a system when AppLocker is enabled and the system is not on the internet.
  • Fixed an issue with credential roaming when Windows Hello for Business is enabled.
  • Fixed an issue that prevents performance monitoring tools from displaying logged data for single instance counter objects.
  • Fixed an issue that prevents the Chromium-based Microsoft Edge from working. This issue occurs when Microsoft Edge is used in combination with Microsoft App-V and fonts are enabled inside the virtual environment.
  • Fixed an issue that might cause a black screen or delay signing in to Hybrid Azure Active Directory joined machines. Additionally, there is no access to
  • Fixed an issue that causes the system to stop working and generates error code 0xC9.
  • Fixed an issue with 7.1 channel audio technology.
  • Fixed an issue that turns on Caps lock unexpectedly when using RemoteApp. 31259510
  • Enabled Windows to retrieve updated printer capabilities to ensure that users have the proper set of selectable print options.
  • Updated support for hole punch and stapling locations for print jobs with long edge first paper feed direction on certain printers.
  • Fixed an issue with high memory usage when performing XSLT transforms using MSXLM6.
  • Fixed an issue that might cause File Explorer and other applications to stop responding for several minutes. This issue occurs after a client reconnects to the corporate network and attempts to use mapped drives to access file shares on the corporate network.
  • Fixed an issue that prevents Server Message Block 1 (SMB1) clients from accessing the SMB share after restarting the LanmanServer service.
  • Fixed an issue that might cause the cluster network interface to stop working for a short time. As a result, the network interface controller (NIC) is marked as failed. When the network is operational again, the system might not detect that the NIC is working and the NIC remains in a failed status.
  • Fixed an issue with signing in to a device that is in the current domain by using the default user profile of a device that is in a different, but trusted domain. The profile service of the current domain cannot retrieve the default user profile from the trusted domain and uses the local default user profile instead.
  • Fixed an issue that causes a device to stop working if you delete files or folders that OneDrive syncs.
  • Fixed an issue that prevents Windows from activating Windows 10, version 2004 using the OA 3.0 key after installing KB4598291.
  • Fixed an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows.
  • Fixed an issue that prevents users from using the Remote Desktop Protocol (RDP) to connect to a Windows Server 2019 device that is in Desktop Experience mode.
  • Fixed an issue to allow our enterprise partners to work with the Microsoft Support program to create customized mitigations.
  • Fixed an issue that might cause a blue screen when attempting to print to certain printers using some apps and might generate the error, APC_INDEX_MISMATCH.
  • Fixed an issue with an HTTP Keep-Alive connection in Azure Front Door. After completing a previous request and response to keep the connection open, Azure Front Door will try to reuse the connection. After an idle timeout, a race condition might occur that closes the Transmission Control Protocol (TCP) connection. As a result, the client might fail with an invalid server response.
  • Fixed an issue that causes Remote Desktop sessions to end unexpectedly
  • Fixed an elevation of privilege security vulnerability documented in CVE-2021-1640 related to print jobs submitted to "FILE:" ports. After installing Windows updates from March 9, 2021 and later, print jobs that are in a pending state before restarting the print spooler service or restarting the OS will remain in an error state. Manually delete the affected print jobs and resubmit them to the print queue when the print spooler service is online.
  • Security updates to the Windows Shell, Windows Fundamentals, Windows Management, Windows Apps, Windows User Account Control (UAC), Windows Virtualization, Windows Kernel, the Microsoft Graphics Component, Internet Explorer, Microsoft Edge Legacy, and Windows Media.

Catch up on all the changes from the previous Windows 10 updates

Seeing a feature that isn't listed here? Perhaps it was added in a previous Windows 10 update. Check out our changelogs for those below!

Zac Bowden
Senior Editor

Zac Bowden is a Senior Editor at Windows Central. Bringing you exclusive coverage into the world of Windows on PCs, tablets, phones, and more. Also an avid collector of rare Microsoft prototype devices! Keep in touch on Twitter and Threads