Microsoft Windows Server
OSMicrosoft Windows Server 2025 is the newest actively maintained release, currently at patch 10.0.26100. 6 of 20 tracked cycles remain supported. The next cycle scheduled to reach end-of-life is 2012-r2, on October 10, 2023.
Support pattern
How Microsoft Windows Server has behaved across the cycles tracked here, rather than what its policy documents state. Useful for judging how much runway a version is likely to have before you commit to it.
Support windows are getting shorter: the most recent cycles run about 90 months less than the earlier ones.
Computed from release and end-of-life dates tracked for Microsoft Windows Server. Medians are used rather than averages so one unusually short or long release does not skew the figure. Cycles with no recorded end-of-life date are excluded from the support window.
How Windows Server versioning, EOL & security support work
Microsoft names most Windows Server releases after their release year (2016, 2019, 2022, 2025), governed by Microsoft's public Lifecycle Policy. Each release follows a Fixed Lifecycle Policy defining a Mainstream Support phase followed by an Extended Support phase, and for some versions, an optional paid Extended Security Updates (ESU) program available once Extended Support itself has ended.
Microsoft ships fixes for Windows Server vulnerabilities through its regular security update process, tied to CVE-linked advisories, for any release still within Mainstream or Extended Support, or covered by a paid ESU subscription. Once a release is past all of those, newly discovered vulnerabilities stay unfixed unless the system is upgraded or enrolled in ESU.
Sources: Microsoft Lifecycle: Windows Server products, Product Lifecycle FAQ: Extended Security Updates
Release lifecycle
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