Millions of Windows users could face update problems in 2027 if their computers fail to receive a set of important security certificate changes. Microsoft says certificates used to establish trusted connections to Windows Update are approaching expiration, with two deadlines falling in May and June 2027.
The change is part of routine security maintenance, but systems that miss the required updates could lose the ability to connect to Windows Update and receive further updates through that service.
Microsoft says most devices that are properly maintained will be covered by ordinary monthly updates. The greater concern is older installations, systems with updates disabled and specialised computers that require administrators to install specific patches.
Importantly, this is not a warning that all Windows computers will stop updating in 2027. The risk depends on the Windows version, servicing arrangement and whether the required certificate transition has been completed.
Which Windows Versions Are Affected?
Microsoft has identified different requirements for specific Windows client and server releases.
Deadline: May 17, 2027
The earlier deadline applies to these long-term servicing versions:
- Windows 10 Enterprise LTSC 2019
- Windows Server 2019
- Windows Server 2016
Administrators should install the July 2026 Windows security update or a later applicable update before the deadline.
Deadline: June 19, 2027
The later deadline covers these versions and servicing groups:
- Windows 11, version 24H2, and Windows Server 2025: Install the September 2025 Windows security update or a later applicable update.
- Other supported Windows 11 versions and Windows Server 2022: Install the July 2026 Windows security update or a later applicable update.
- Supported Windows 10 versions: Install the July 2026 Windows security update or a later applicable update.
Microsoft says Windows 11 version 25H2 and later do not require additional action for this certificate transition.
These requirements are based on Microsoft's published guidance. The exact update needed can depend on the device's servicing channel and management configuration, so organisations should check the official instructions before assuming that a particular patch is sufficient.
Why the Certificate Change Matters
Digital certificates help computers establish trust when connecting to online services. Windows Update relies on certificate-based trust to verify that a device is communicating with Microsoft's legitimate update infrastructure.
Certificates have expiration dates. Before they expire, the systems that rely on them must be prepared to use replacement certificates.
If an affected computer misses the transition, it could encounter problems connecting to Windows Update. That could prevent it from receiving future updates through the service, including security fixes.
Microsoft is distributing the necessary changes through its regular update process for most eligible systems. However, computers that have been offline, left unpatched or configured to block updates may need intervention.
There is also an important exception: Microsoft's notice says the certificate rotation does not apply to devices receiving updates through Windows Server Update Services (WSUS). Businesses using WSUS should follow the applicable guidance for their update infrastructure.
How to Check and Protect Your PC
Users can reduce the risk well before the 2027 deadlines by checking their Windows version and installing applicable updates.
1. Identify your Windows version. Open Settings, select System, then About. Check the Windows edition and version displayed under Windows specifications.
2. Open Windows Update. On Windows 11, go to Settings, then Windows Update. On Windows 10, open Settings and select Update & Security, followed by Windows Update.
3. Install available updates. Select Check for updates, install applicable updates and restart the computer if prompted. Continue installing subsequent monthly security updates.
4. Check older and specialised systems carefully. Computers running Windows 10 Enterprise LTSC 2019, Windows Server 2019 or Windows Server 2016 deserve particular attention because of the earlier May deadline. Devices running other listed versions should meet the requirements for their applicable deadline.
5. Contact your IT administrator if necessary. Work computers, school systems and server installations may follow centrally managed update policies. Their administrators should verify the installed updates and certificate-transition requirements.
Installing the latest available update is an important first step, but administrators should confirm that the required change has been applied to their specific system.
The Bottom Line
Microsoft's certificate transition is a reminder that operating-system maintenance is about more than new features. Security updates also help preserve the trusted connections that Windows relies on to deliver future fixes.
Most properly updated devices should not require special intervention. The main risk lies with systems that miss the applicable updates or use configurations requiring additional administrative work.
Windows Update is not being discontinued in 2027. But computers that fail to complete the required certificate transition could lose access to future updates through the service. Checking the version, installing applicable patches and reviewing Microsoft's guidance now can help avoid last-minute problems.
