- Microsoft has released Windows 10 builds 19045.6216 and 19044.6216 as the August 2025 Patch Tuesday update for version 22H2 and 21H2.
- It introduces stability fixes, resolves issues with the ESU enrollment wizard, and adds SKUSiPolicy Secure Boot protections to block rollback of vulnerable system files.
UPDATED 8/12/2025: Windows 10 build 19045.6216 (KB5063709) is now available as a mandatory install through the Stable Channel for version 22H2. Windows 10 21H2 is also getting the security update KB5063709, but as build 9044.6216. This is a security update that Microsoft is releasing as part of the Patch Tuesday update for August 2025.
According to the official notes (Stable Channel (optional) notes and Release Preview Channel notes), builds 19045.6216 and 19044.6216 for Windows 10 don’t introduce any new features. Instead, it introduces a fix for the Extended Security Updates (ESU) enrollment wizard, where some users were experiencing issues clicking the “Enroll now” button.
This preview for the August 2025 update adds the ability to deploy “SKUSiPolicy” VBS Anti-rollback protections through the Secure Boot “AvailableUpdates” Registry key.
The SKUSiPolicy.p7b is a revocation policy signed by Microsoft that blocks outdated or vulnerable VBS system files from loading. It prevents attackers with admin privileges from rolling back system files to an older version that may be vulnerable to attacks.
Once the policy is applied, it can lock the policy to the device’s UEFI firmware, making it persistent across reboots.
The AvailableUpdates key acts as a trigger for Secure Boot to recognize and apply updates like SKUSiPolicy. By modifying this key, admins can deploy the anti-rollback protections without needing manual intervention during boot.
In addition, this update fixes a problem causing stability issues after installing the May 2025 security update.
Finally, the update KB5063709 updates the Country and Operator Settings Asset (COSA) profiles.
Microsoft never defines the name of an update when it’s available in the Release Preview Channel. When the updates are ready for the Stable Channel as a preview, they’ll be known as a non-security update. It’s not until they become fully available during the Patch Tuesday Update release that the company will label them, for example, in this case, as the “August 2025 Security Update.”
Older versions of Windows 10
Furthermore, Microsoft is releasing updates available for older operating system versions, including 1809, 1607, and 1507. For example, the company is rolling out the update KB5063877 for version 1809, bumping the build number to 17763.7678 with fixes.
Windows 10 1607 receives the update KB5063871, which bumps the version to build 14393.8330, and addresses an issue with the DHCP Server feature.
Finally, Windows 10 1507 is getting the update KB5063889, which bumps the build number to 10240.21100 and rolls out miscellaneous security improvements to internal functionality.
Installation process
To download and install this quality update for Windows 10, open the “Windows Update” settings, turn on the “Get the latest updates as soon as they’re available” option, and click the “Check for Updates” button. It’s important to note that it may take some time before you see the new changes on your computer as Microsoft gradually rolls out improvements.
Windows 10 end of support
Microsoft announced the end of support for Windows 10 on October 14, 2025, even though they are still releasing maintenance updates. After this date, Microsoft will no longer provide security updates, bug fixes, features, or technical support for Windows 10. This lack of updates will leave your system vulnerable to security threats and may decrease its performance.
Since the software giant will no longer provide updates or support for Windows 10, you should upgrade to Windows 11 or another operating system, such as Linux Mint, or plan to purchase a new device.
If you want to continue using Windows 10, Microsoft now offers Extended Security Updates (ESU). This service was originally reserved for organizations needing to run older operating systems beyond the official support period, but it is now also offered to regular consumers.
Update July 17, 2025: Microsoft has released the update KB5062649 to address an installation issue. Originally, the build number was 19045.6156. However, on July 15, it was updated to 19045.6159.
Update July 22, 2025: The update is now available as an optional update through the Stable Channel with the improvements as in the Release Preview Channel.
Update August 12, 2025: This content has been updated with new information, and it’s been revised to ensure accuracy.
Mauro Huculak is a Windows How-To Expert and founder of Pureinfotech in 2010. With over 22 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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