# Upgrade Windows Server 2016 to 2025 in place

> Yes, Windows Server 2016 can upgrade in place straight to 2025. Supported paths, blockers, the licence you need, and when a clean rebuild is safer.

Source: https://wharfcloud.co.uk/guides/upgrade-windows-server-2016-to-2025 · Last updated 21 October 2026 · WharfCloud

Published 21 October 2026. Reading time about 8 minutes.

## Short answer

Yes. Microsoft supports an in-place upgrade from Windows Server 2016 directly to Windows Server 2025, as well as to 2019 or 2022, for servers that are not in a cluster. You need a new Windows Server 2025 licence, a tested full backup, hardware or a virtual machine that meets 2025's requirements, and confirmation that every application on the server supports 2025. If the server has years of accumulated software, or runs a domain controller or an old line-of-business app, a clean rebuild with a migration is usually the safer route.

## Supported upgrade paths from Windows Server 2016

Table: In-place upgrade paths from Windows Server 2016 (Microsoft, installation media)

| Target version | In-place upgrade from 2016 | Microsoft mainstream support | Microsoft extended support |
| --- | --- | --- | --- |
| Windows Server 2025 | Supported | Until 13 November 2029 | Until 14 November 2034 |
| Windows Server 2022 | Supported | Ended 13 October 2026 | Until 14 October 2031 |
| Windows Server 2019 | Supported | Ended 9 January 2024 | Until 9 January 2029 |

Microsoft's upgrade guidance says that from Windows Server 2025, servers that are not clustered can upgrade up to four versions at a time, which is why 2016 can go straight to 2025. Clusters using a cluster OS rolling upgrade can only move one version at a time.

If you are going to touch the server anyway, 2025 is the sensible target: it is the only one of the three still in mainstream support, and some vendors test only against releases in mainstream support. Pegasus says exactly that for Opera 3.

## What blocks or complicates an in-place upgrade

Microsoft lists restrictions for in-place upgrades of licensed Windows Server. The ones small businesses meet most often:

- **Domain controllers** need extra steps; Microsoft has separate guidance for upgrading them, and many administrators prefer to add a new domain controller and retire the old one.
- **Server Core and Desktop Experience** cannot be swapped during the upgrade.
- **Language** cannot be changed during the upgrade.
- **Edition** stays the same (Standard to Standard) unless you move up to Datacenter; you cannot move down.
- **NIC Teaming** has to be disabled before the upgrade.
- **Evaluation copies** cannot be upgraded to; install those clean.
- **Hardware:** Windows Server 2025 needs a 64-bit processor that supports SSE4.2 and POPCNT, among other instructions. Older hosts and some virtual machine settings fail this check.

## The licence question

Microsoft's guidance is blunt: unlike Windows client, each Windows Server upgrade requires a separate licence, and you need a valid product key and activation method for the target version. Your 2016 licence does not cover 2025 unless it had Software Assurance that included new versions.

Windows Server is licensed per core, and Remote Desktop users and devices need their own access licences. If the upgrade is also the moment you consider moving the server out of the office, compare the cost of buying licences outright with a hosted server where the Windows licence is part of the monthly price.

## Checklist: in-place upgrade or clean rebuild?

Table: Signals that point one way or the other

| Signal | Points to |
| --- | --- |
| A single-purpose server (file share, print, one app) with a clean history | In-place upgrade |
| Every application vendor confirms support for Windows Server 2025 | In-place upgrade |
| The server is a domain controller | Rebuild: add a new DC, then retire the old one |
| Years of installed tools, old drivers or unknown scheduled tasks | Rebuild and migrate |
| The hardware is out of warranty or fails 2025's CPU requirements | Rebuild on new hardware or a hosted server |
| An application vendor does not support 2025 | Rebuild on the newest release the vendor supports, or plan the application's replacement |

## If you upgrade in place: the safe order

1. **Inventory.** List every role, application, service account and scheduled task on the server, and who uses it.
2. **Check vendor support.** Confirm Windows Server 2025 support with each application vendor, including any SQL Server version on the server.
3. **Back up and test the restore.** Microsoft asks for a full backup of the operating system, apps and data, with a restore test to prove it works.
4. **Record the current state.** Microsoft suggests capturing system information (for example with systeminfo) before you start.
5. **Upgrade in a maintenance window.** From Windows Server 2016, use installation media and run Setup: Microsoft's Windows Update upgrade route to 2025 needs Windows Server 2019 or 2022 as the starting point. The server restarts several times.
6. **Test with real users.** Before you call it done, have the people who use each application try their normal tasks.

> **Several servers to plan?** Our fixed-price [Windows Server 2016 migration plan](https://wharfcloud.co.uk/windows-server-2016-end-of-support) covers up to five servers: inventory, dependencies and vendor checks, the options for each server and a written, costed plan. If you would rather not own the server afterwards, a [Managed Windows Server](https://wharfcloud.co.uk/managed-servers/windows) in London includes the licence and the move.

## Frequently asked questions

### Can I upgrade Windows Server 2016 directly to 2025?

Yes. Microsoft supports an in-place upgrade from Windows Server 2016 to Windows Server 2025 for non-clustered servers. Clusters must move one version at a time with a cluster OS rolling upgrade.

### Is the upgrade free?

No. Microsoft says each Windows Server upgrade needs a separate licence for the target version, unless your licences had Software Assurance covering new versions.

### Should I upgrade to 2022 or 2025?

2025, unless an application vendor only supports 2022. Windows Server 2022 left mainstream support on 13 October 2026; 2025 stays in mainstream support until 13 November 2029.

### Can I upgrade a domain controller in place?

Microsoft has separate guidance for domain controllers, and many administrators prefer to add a new domain controller on the new release and retire the old one. It is usually the lower-risk path.

### Will my applications keep working?

Only the vendor can confirm that. Check each one before you start, including the SQL Server version if the application uses a database.

### What if I cannot upgrade before 12 January 2027?

Paid Extended Security Updates can bridge a gap if you qualify. See our guide to [Windows Server 2016 ESU](https://wharfcloud.co.uk/guides/windows-server-2016-extended-security-updates).

## Sources

- [Microsoft Learn: Plan your Windows Server upgrade (supported paths and restrictions)](https://learn.microsoft.com/en-us/windows-server/get-started/upgrade-overview)
- [Microsoft Learn: Perform an in-place upgrade of Windows Server](https://learn.microsoft.com/en-us/windows-server/get-started/upgrade-in-place)
- [Microsoft Learn: Hardware requirements for Windows Server](https://learn.microsoft.com/en-us/windows-server/get-started/hardware-requirements)
- [Microsoft Lifecycle: Windows Server 2025](https://learn.microsoft.com/en-us/lifecycle/products/windows-server-2025)
- [Microsoft Lifecycle: Windows Server 2022](https://learn.microsoft.com/en-us/lifecycle/products/windows-server-2022)
- [Microsoft Lifecycle: Windows Server 2019](https://learn.microsoft.com/en-us/lifecycle/products/windows-server-2019)
- [Pegasus: Opera 3 Software Requirements Guide (June 2026), PDF](https://docs.pegasus.co.uk/Guides/Latest/Software_Requirements_Guide.pdf)

---

WharfCloud is a trading name of Sunucu Internet Services Consultancy Ltd, registered in England and Wales, company number 12963678. Not VAT registered.
Support: engineers Monday to Friday, 08:00 to 18:00 UK time. Critical incidents: A person responds to critical incidents within 1 hour (Every day, 07:00 to 23:00 UK time). Automated monitoring and automated recovery overnight and at weekends.
Contact: hello@wharfcloud.co.uk · https://wharfcloud.co.uk/contact