Windows 10 update settings with purple background

Windows 10 out-of-band update KB5015020 releases for versions 21H2, 21H1, 20H2

Windows 10 receives an important out-of-band update to address authentication problems.

  • Microsoft releases update KB5015020 for Windows 10 21H2, 21H1, and 20H2.
  • The update bumps the version number to build 19044.1708.
  • The update KB5015020 fixes authentication failures after the previous update.

On May 19, 2022, Microsoft released a new out-of-band update known as the KB5015020 for Windows 10 21H2, 21H2, and 20H2. This non-security update is designed to address authentication failures with services on servers or clients after installing the May 10 update on a domain controller.

In addition, the update bumps the version number to build 19042.1708 (20H2), 19043.1708 (21H1), and 19044.1708 (21H2) and fixes a bug with Microsoft Store apps.

The same fix for authentication failures is also available for versions 1809 and 1607.

If you prefer downloading and installing the May 2022 update manually, you can download it from the Microsoft Update Catalog website.

Update KB5015020 fixes and changes for Windows 10

These are the fixes and improvements available with the latest update preview of Windows 10:

  • Addresses a known issue that might cause authentication failures for some services on a server or client after you install the May 10, 2022 update on domain controllers. These services include Network Policy Server (NPS), Routing and Remote access Service (RRAS), Radius, Extensible Authentication Protocol (EAP), and Protected Extensible Authentication Protocol (PEAP). The issue affects how the domain controller manages the mapping of certificates to machine accounts. This issue only affects servers that are used as domain controllers; it does not affect client Windows devices.
  • Addresses an issue that might prevent the installation of Microsoft Store apps when you enable Control-flow Enforcement.

Install update KB5015020 for Windows 10

The update is available immediately and it will download and install automatically. However, you can always force the update from Settings Update & Security > Windows Update, click the Check for updates button, and use the option to install the optional update.

About the author

Mauro Huculak is a Windows How-To Expert and founder of (est. 2010). With over 21 years as a technology writer and IT Specialist, Mauro specializes in Windows, software, and cross-platform systems such as Linux, Android, and macOS.

Certifications: Microsoft Certified Solutions Associate (MCSA), Cisco Certified Network Professional (CCNP), VMware Certified Professional (VCP), and CompTIA A+ and Network+.

Mauro is a recognized Microsoft MVP and has also been a long-time contributor to Windows Central.

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