January 12, 2027: the date
Extended support for Windows Server 2016 ends on January 12, 2027. Mainstream support already ended in January 2022; after January 12, Microsoft will no longer ship security fixes for it, except to organisations that buy Extended Security Updates (ESU), where Microsoft offers them.
The server will not stop that day. It will keep booting and serving your applications and databases. That is what makes the deadline easy to push back, and why it is better to decide now, calmly, than in a rush after an incident.
What actually happens after end of support
- Vulnerabilities stay open. Any flaw found after January 12, 2027 will no longer be fixed on your servers, including those used by ransomware.
- Insurers and customers ask. Security questionnaires, cyber insurance, ISO 27001, NIS 2: a system that no longer gets fixes is an answer that is harder and harder to defend.
- Vendors move on. Business software vendors (ERP, payroll, accounting) drop unsupported systems from their certified configurations.
- SQL Server is often in the same boat. Many Windows Server 2016 machines host SQL Server 2016, out of support since July 14, 2026 (see our SQL Server 2016 article). Migrating both together saves a second project, a second cutover and a second round of testing.
Step 1: find the affected servers
On each server, this read-only PowerShell script returns the Windows version:
# Windows version of each server (PowerShell, read-only)
Get-CimInstance Win32_OperatingSystem |
Select-Object CSName, Caption, Version, BuildNumber
# BuildNumber 14393 = Windows Server 2016For your database servers, the same answer comes from SQL Server:
/* From SQL Server: the operating system is part of @@VERSION */
SELECT SERVERPROPERTY('ServerName') AS instance, @@VERSION AS full_version;
/* "... on Windows Server 2016 ..." = affected server */Do not forget the servers nobody looks at: domain controllers, file and print servers, test machines, and servers a supplier installed for a line-of-business application.
Step 2: pick an option per server
| Option | For whom | Worth knowing |
|---|---|---|
| New server on Windows Server 2025 or 2022 | Most cases | Side-by-side migration: you test before the cutover and the old server stays intact as a fallback. |
| In-place upgrade | Simple servers, no SQL Server or critical role | Faster, but no easy way back: full backup and a test on a copy first. |
| Move to the cloud (Azure, or a managed service) | Applications that are ready, or databases that can go to Azure SQL | Compare the monthly cost with a server you have already paid off, and check latency to your users. |
| ESU (Extended Security Updates) | Servers that cannot migrate in time | Paid, and critical security fixes only. A bridge of a few months, not a destination: have your reseller confirm the offer and price. |
Windows Server 2025 is supported until November 2034 and Windows Server 2022 until October 2031. Check what your software vendors certify first: it often settles the choice.
Step 3: plan before the holidays
Between ordering licences, getting a server or virtual machine, testing and an out-of-hours cutover, a clean migration takes several weeks. With the year-end holidays, a project that does not start in November will not be done by January 12.
- run the inventory above;
- rank servers: critical, important, secondary;
- ask each vendor for its certified versions;
- set a cutover date for the critical servers, even a provisional one.
Do your servers host SQL Server?
That is our speciality. Our end-of-support flash audit (€1,490 excl. VAT, delivered within a week, fully credited against the migration if you hand it to us) covers Windows and SQL Server in one plan: inventory, target version, migration order, cutover and rollback.
Not sure you need it yet? A 15-minute call is enough to know where you stand: book a 15-minute call. See also our SQL Server migration service.
