Microsoft is embarking on a significant update to the certificates that authenticate communication between Windows PCs and genuine Windows Update servers. This change, announced on October 8, is crucial for maintaining the flow of updates to users’ devices. The current certificates are set to expire on May 17 and June 19, 2027, and machines that do not transition to the new certificates will find themselves unable to receive updates.
What Users Need to Know
Fortunately for most users, the transition will be seamless. The new certificates will be included in the regular monthly security updates, meaning that users typically won’t need to take any additional action. Here’s a breakdown of what different versions of Windows will require:
- Windows 11 25H2 and later: No action required.
- Windows 11 24H2: Must install the September 2025 security update or newer.
- Other supported Windows 11 and Windows 10 versions: Need the July 2026 update or later before June 19, 2027.
- Windows 10 Enterprise 2019 LTSC, Windows Server 2019, and Windows Server 2016: Face the earlier deadline of May 17, 2027.
Microsoft has made it clear that devices running unsupported versions will lose access to Windows Update services, resulting in a halt to all updates. The company’s primary recommendation is straightforward: upgrade to a supported version.
For home users, this situation predominantly affects Windows 10 PCs that were not enrolled in Extended Security Updates (ESU) after the operating system reached its end of life in October 2025. These machines likely missed the critical July 2026 patch. However, Microsoft has extended ESU coverage until October 12, 2027, suggesting that enrolling in this program and installing the necessary updates before June could ensure access to the new certificates.
This announcement follows Microsoft’s earlier initiative to refresh Secure Boot certificates, which are also set to expire in late June 2026. Users are encouraged to review their update history to confirm they have received a cumulative update from July 2026 or later, ensuring their systems remain secure and up to date.
