Windows Server 2016 end of support in 2027: how to upgrade

This guide is for whoever is responsible for a business system that runs on Windows Server 2016, and has to decide what happens to that server. Extended support ends on 12 January 2027. From that date Microsoft issues no more security updates, bug fixes or technical support for it, although the server carries on running. Our Windows Server 2016 end of support page explains what that means. This guide covers the upgrade: the routes Microsoft supports, the order of the work and what to check on the applications.

Before you start

Find out:

how many servers run Windows Server 2016, and whether each is physical or virtual;
what each one does, and who in the business depends on it;
who supplies each application, and which Windows Server versions they support;
what licences you hold. Microsoft states that each Windows Server upgrade requires a separate licence.

Have in hand a full backup of each server that has been restored as a test, administrator access, installation media and a product key for the target version, and an agreed maintenance window.

In our judgement the operating system is the smaller part of the work. Steps 1, 3 and 6 below, which are about the applications, usually take most of the effort. The upgrade or cutover in step 7 is short by comparison.

1. Find every server and what runs on it

This command reports the version of a server you are logged on to:

Get-ComputerInfo -Property WindowsProductName

For each Windows Server 2016 machine, write down:

the roles it performs, such as web server, file server or domain controller;
the applications and databases installed on it;
scheduled tasks and Windows services, with the accounts they run under;
certificates, with their expiry dates;
what connects to it: other systems, file shares and firewall rules that refer to it by name or address.

2. Choose the target version

Microsoft’s upgrade documentation says a Windows Server 2016 machine can be upgraded in place, using installation media, to any of the three later versions in a single step. That includes Windows Server 2025, which accepts direct upgrades from Windows Server 2012 R2 and later.

Target	Supported until	In place from 2016 in one step	.NET Framework included	Oldest SQL Server Microsoft supports on it
Windows Server 2019	9 January 2029	Yes	4.7.2	2012 (with Service Pack 4)
Windows Server 2022	14 October 2031	Yes	4.8	2017
Windows Server 2025	14 November 2034	Yes	4.8.1	2019

Windows Server 2019 has little more than two years left, so it is only worth choosing when an application supports nothing newer. Between 2022 and 2025, the applications decide.

3. Check each application against the target

Supplier support. Ask each supplier in writing which Windows Server versions their product is supported on.
SQL Server. The table shows the catch. SQL Server 2016 is supported on Windows Server 2019, with Service Pack 3, but not on Windows Server 2022 or 2025. SQL Server 2017 is not supported on 2025. A server running SQL Server 2016 needs the database upgraded as part of the same project. Our SQL Server 2016 page covers that.
.NET Framework. Windows Server 2016 shipped with .NET Framework 4.6.2, which goes out of support on the same day. An application still targeting 4.6.2 should be moved to 4.8 as part of the work. The newer servers include a later version, and Microsoft describes later 4.x versions as compatible in-place updates, so applications are expected to keep running. Test them anyway. Our .NET Framework page has more.
IIS settings. IIS is the Windows web server. Application pool identities, bindings, authentication modes and rewrite rules have to be recorded and reproduced on a new server.
Scheduled tasks and service accounts. Check that each account still exists, and that somebody knows its password.
Certificates. These have to be exported with their private keys to move to a new server.
Drivers and licence dongles. Database drivers, printer drivers and USB licence keys are often installed by hand and missing from any documentation. Check that each has a version for the target.
Removed features. Windows Server 2025 removes the SMTP Server feature, the standalone Internet Explorer application, the IIS 6 Management Console and Windows PowerShell 2.0. An application that sends its email through the server’s own SMTP service will need another relay.

4. Choose in-place upgrade or a new server

In-place upgrade. Setup installs the new version over the old one and keeps settings, roles, applications and data. Microsoft describes it as the fastest path on the same hardware. It needs downtime, and the server restarts several times. It suits a virtual machine doing one job, where every application is supported on the target. Microsoft sets these limits:

Do not upgrade a domain controller in place. Build a new one and retire the old.
A clustered server uses a rolling upgrade instead, one version at a time.
You cannot switch between Server Core and Server with Desktop Experience during the upgrade.
NIC Teaming has to be disabled first and re-enabled afterwards.

A new server. You build a server on the target version, install the applications, move the data and switch over. Microsoft provides Windows Server Migration Tools for moving roles and the Storage Migration Service for file servers. This route suits old hardware and servers that have gathered years of hand-installed components. It also suits anything running SQL Server 2016. The old server stays untouched as a fallback, which is why many teams prefer this route even where an in-place upgrade is supported.

5. Consider a cloud virtual machine

If the server is physical hardware of the same age, the new server does not have to be another box in the same room. Moving to a hosted virtual machine in the same project avoids buying hardware, and it adds questions about network links, licensing and backups. Our cloud migration page describes how we rehearse such a move.

6. Rehearse

For an in-place upgrade, copy the virtual machine and upgrade the copy on an isolated network. For a new server, build it and restore a copy of the data.
Run every application through the work the business depends on, including scheduled tasks, printing, emails and interfaces to other systems.
Record each thing that breaks and its fix.
Repeat until a run produces nothing new.

7. Upgrade or cut over, with a way back

For an in-place upgrade, Microsoft’s procedure runs in this order:

Take a full backup of the operating system, applications and data, and test that it restores.
Save diagnostic information somewhere off the server. Microsoft suggests the output of Get-ComputerInfo, systeminfo.exe and ipconfig /all.
Run setup.exe from the installation media and choose Keep files, settings, and apps.
Confirm the version afterwards and test every application.

The way back is the backup, or a snapshot of the virtual machine taken just before. If the upgrade fails, the Setup logs are in C:\Windows\Panther.

With a new server, the cutover is a change of name or address. Going back means reversing that change, provided nothing that matters has yet been written to the new server. Keep the old server, isolated or switched off, until the new one has been through a month-end.

If a server cannot move in time

Microsoft announced Extended Security Updates for Windows Server 2016 in February 2026. Its documentation says they provide Critical and Important security updates for up to three years after end of support. It describes delivery through Azure Arc, Microsoft’s service for managing servers outside Azure, and says Software Assurance or an equivalent server subscription is required. Enrolment opened on 3 August 2026 and billing begins on 13 January 2027. Check the current terms and cost with your licensing supplier. This is a paid stopgap, worth having only if the time it buys is used to move.

What usually goes wrong

An application is found late that its supplier does not support on the new version.
SQL Server 2016 is on the server, and nobody planned a database upgrade.
A component installed by hand years ago is missing on the new server.
A scheduled task ran under the account of someone who has left.
Other systems refer to the old server by an address written into their configuration.
The work is left until December, when holidays and change freezes take most of the remaining weeks.

When to get help

The Windows upgrade itself is work for whoever looks after your servers, and we do not provide general IT support. Where we help is with the bespoke applications on the server: finding out what they depend on, getting them running on a supported version and bringing the database and framework up to date in the same project. If nobody is sure what an application needs, a fixed-price code audit produces that inventory.