Windows Server end-of-support dates
| Version | Mainstream support ended | Extended support ends | What it means |
|---|---|---|---|
| Windows Server 2012 / 2012 R2 | Oct 2018 | 10 Oct 2023 (ended) | Only patched through ESUs. In Azure, ESUs are included. |
| Windows Server 2016 | Jan 2022 | 12 Jan 2027 | Plan migration or ESUs now |
| Windows Server 2019 | Jan 2024 | 9 Jan 2029 | Supported, but on extended support (security fixes only) |
| Windows Server 2022 | Oct 2026 | 14 Oct 2031 | Supported |
Running a server after end of support means no new security patches. Many cyber insurance policies, Cyber Essentials and supplier security questionnaires treat that as a material risk.
Your options for Windows Server 2016
- Upgrade in place on existing hardware. This works if the hardware is recent and the application supports a newer Windows version. You still own the hardware refresh cycle.
- Buy Extended Security Updates on-premises. ESUs are available through Azure Arc for servers that stay on-premises. Microsoft's guidance is that billing for Windows Server 2016 ESUs starts on 13 January 2027, pay-as-you-go, and requires Software Assurance.
- Migrate to Azure. Windows Server 2016 VMs in Azure receive ESUs at no additional cost. That removes the hardware and gives you time to upgrade or modernise on your own schedule. For most organisations with ageing hardware, this is the strongest option.
How a Windows Server migration to Azure works
- Discover. The Azure Migrate appliance inventories your Windows servers and collects CPU, memory, disk and network data, usually over 2–4 weeks.
- Right-size. We use that data to choose Azure VM sizes and disk types. This is where most cost savings are made, because on-premises servers are commonly over-provisioned.
- Replicate. Servers replicate continuously to Azure in the background with no impact on users.
- Test. Each server is test-migrated into an isolated Azure network so applications can be checked before go-live.
- Cut over. In an agreed window (usually out of hours) we stop the source, do a final sync and switch users across. The rollback path stays open until you sign off.
Keeping Windows Server costs down in Azure
- Azure Hybrid Benefit: reuse eligible Windows Server licences with Software Assurance.
- Reserved VM instances: commit for one or three years for large discounts (Microsoft quotes up to 72% versus pay-as-you-go).
- Auto-shutdown: switch off dev/test servers out of hours.
- Right-sizing after go-live: review real usage after 30 days and downsize where possible.
See our Azure migration cost guide for indicative costs.
Planning a migration? Get a free assessment covering scope, ballpark cost and funding eligibility.
Get my free assessmentFrequently asked questions
When does Windows Server 2016 support end?
Windows Server 2016 mainstream support ended on 11 January 2022, and extended support ends on 12 January 2027. After that date, servers only receive security updates through paid Extended Security Updates, or for free when running in Azure.
Do I have to upgrade the operating system when I move to Azure?
No. You can move Windows Server 2016 (and 2012/R2) servers to Azure as they are, keep receiving security updates via ESUs, and upgrade the OS later. In practice we often combine migration with an in-place upgrade where the application supports it.
Can I reuse my Windows Server licences in Azure?
Yes, if they're covered by Software Assurance or an eligible subscription. Azure Hybrid Benefit lets you apply them to Azure VMs so you only pay for compute, not the Windows licence, which is a significant saving.
What about domain controllers and file servers?
Domain controllers are usually extended into Azure rather than "moved", by adding new DCs in Azure and retiring old ones. File servers can move to Azure VMs, Azure Files (often with Azure File Sync) or SharePoint, depending on how they're used.
What if an application vendor doesn't support Azure?
Most Windows applications that run on VMware or Hyper-V run on Azure VMs unchanged. Where a vendor has specific requirements, we check them during the assessment and, if needed, test the application in Azure before committing.