Windows Server End of Support: The Dates That Matter in 2026 and 2027

The short answer: if you run Windows Server 2012 or 2012 R2, paid Extended Security Updates finish on 13 October 2026 and there is no further extension. Windows Server 2016 loses support on 12 January 2027. Windows Server 2022 leaves mainstream support on 13 October 2026 but keeps security updates until 2031. And if you still run Exchange Server 2016 or 2019 on site, both have been unsupported since October 2025.

The dates

What "out of support" actually means

The server keeps running. What stops is security updates, which matters more every month that passes. It also has knock-on effects:

• Cyber Essentials: the scheme requires software to be licensed and supported, so an unsupported server fails. See our Cyber Essentials guide.
• Insurance and contracts: cyber insurers and customers increasingly ask whether your systems are supported.
• Software vendors: your line-of-business applications will stop being certified on it.

Windows Server 2016: your options before January 2027

1. Upgrade the operating system

Windows Server 2016 can upgrade in place to 2019, 2022 or 2025. Microsoft allows nonclustered servers to jump up to four versions at once when the target is Windows Server 2025, so even a 2012 R2 server can go straight there. Clustered servers advance one version at a time.

In-place upgrades work, but a clean build and migration is usually cleaner on a server that's been in service for years. For domain controllers, Microsoft specifically recommends building a new server, promoting it and demoting the old one, rather than upgrading in place.

2. Replace the hardware too

A 2016-era server is likely to be eight or nine years old, which is past the point where parts and support cost more than they save. Our guide to planning a server refresh covers how to approach it, and rack or tower covers the shape of the replacement.

3. Move the workload to the cloud

Some workloads don't need a server at all once file storage and email are in Microsoft 365. Others run happily as a virtual machine in Azure. Windows Server virtual machines in Azure also receive Extended Security Updates at no extra cost beyond the VM.

4. Buy Extended Security Updates, if you qualify

ESU buys up to three more years of critical and important security updates, and nothing else. Two points catch businesses out:

• You need Software Assurance or a subscription licence. Servers bought with OEM licences and no Software Assurance don't qualify, which rules out many small business servers.
• It's priced per core, annually, with minimums of 8 cores per processor and 16 per server, and the cost is comparable to buying the licence again each year.

For Windows Server 2016, ESU can be arranged through Azure Arc, with billing starting from 13 January 2027. It's a bridge, not a plan.

Exchange Server 2016 and 2019: already out of support

Both reached the end of support on 14 October 2025, and there is no ESU programme for Exchange. If you still host your own mail, this is the most urgent item on the list. The routes are Exchange Online as part of Microsoft 365, or Exchange Server Subscription Edition on site. Our comparison of Microsoft 365 business plans covers the first option.

Windows Server 2025 licensing, briefly

• Licensed by core: you license every physical core, with a minimum of 8 per processor and 16 per server.
• Standard covers two operating system environments (so two virtual machines, or one physical plus one virtual). Buy another full set of core licences for two more.
• Datacenter allows unlimited virtual machines on that hardware, which suits virtualisation hosts.
• CALs are separate. Every user or device connecting needs one, and they must be the same version as the server or newer. Windows Server 2022 CALs do not cover a 2025 server.

Licences and CALs are available from the Apaxon store, and the linked products below are a starting point.

A sensible plan

1. List every server, including virtual machines, and note the version.
2. Check which applications depend on each one, and what the supplier supports.
3. Deal with anything already unsupported first, especially on-premises Exchange and any 2012 R2 server.
4. Diarise Windows Server 2016 for 12 January 2027 and start the work by the summer.
5. Check backups and test a restore before any upgrade. See the 3-2-1 backup rule.

Help from Apaxon

Apaxon supplies Dell and HPE enterprise servers on quote, through Dell Technologies and Arrow Electronics, who handle installation and configuration, and sells Windows Server licences and CALs through the Apaxon store. For planning, migration and ongoing support, see our managed IT services and managed cloud services, browse the Dell range, or request a quote.

Sources

• Microsoft: Windows Server 2016 lifecycle
• Microsoft: Windows Server 2012 R2 lifecycle
• Microsoft: Windows Server 2022 lifecycle
• Microsoft: Extended Security Updates overview
• Microsoft: Extended Security Updates FAQ
• Microsoft: prepare for Windows Server 2016 ESUs with Azure Arc
• Microsoft: install, upgrade or migrate to Windows Server
• Microsoft: Windows Server 2025 licensing guidance
• Microsoft: Exchange Server 2019 lifecycle
• Microsoft: upgrade domain controllers