If you're still on Windows Server 2016, you're out of runway. Extended support ends January 13, 2027 — under four months from now — and a clean server migration takes longer than that once vendor certification and a cutover weekend are in the schedule.
If you're on 2019 or 2022, you have years. Plan the move around your next hardware refresh and land on 2025 when you do.
When does my current server version stop getting security updates?
Microsoft's lifecycle pages give exact dates. Here's where each version stands as of September 2026:
| Version | Mainstream support ends | Extended support ends | Direct in-place upgrade to 2025? |
|---|---|---|---|
| Windows Server 2012 R2 | Ended | Ended October 2023 | Yes |
| Windows Server 2016 | Ended | January 13, 2027 | Yes |
| Windows Server 2019 | Ended | January 10, 2029 | Yes |
| Windows Server 2022 | October 14, 2026 | October 15, 2031 | Yes |
| Windows Server 2025 | November 14, 2029 | November 15, 2034 | — |
Two things jump out of that table. Windows Server 2016 has under four months of patches left. And Windows Server 2022 drops out of mainstream support on October 14, 2026 — weeks away — which means security fixes only, no new features, for the next five years.
Neither of those is a reason to panic about 2022. It is a reason to stop buying new servers to run it.
We covered the 2016 deadline in detail in our Windows Server 2016 end of support guide. The short version: no patches means no cyber insurance renewal and no compliance sign-off, whatever the server is doing.
Can I upgrade straight to Windows Server 2025?
Yes, and this is the part that changed. Microsoft's upgrade documentation confirms that nonclustered systems can now upgrade up to four versions at a time — so 2012 R2, 2016, 2019, and 2022 all have a supported direct in-place path to 2025.
Before 2025, you could only jump two versions. A 2012 R2 box meant two separate upgrades and two separate outages. That's gone.
One exception: failover clusters using cluster OS rolling upgrade still move one version at a time. If you're running a two-node Hyper-V cluster, budget for the extra hop.
Should I do an in-place upgrade or a clean build?
Clean build, almost always. In-place upgrades work, and Microsoft supports them, but they carry forward a decade of accumulated registry cruft, orphaned services, and permissions nobody can explain.
The exception is a domain controller you can't easily rebuild, or an application the vendor only supports on the existing install. Even then, build a new DC alongside and demote the old one rather than upgrading in place.
A clean build also forces the question worth asking: does this need to be a server at all?
Should this workload move to the cloud instead?
For a lot of small businesses, the 2016 server is running a file share and a print queue, and both of those belong in Microsoft 365 now.
File shares move to SharePoint or OneDrive. Print goes to Universal Print or a cloud print service. Once those are out, what's left is often one line-of-business application — and that's a much smaller, cheaper server, or an Azure VM.
Don't assume cloud is cheaper. It often isn't for a steady-state workload that runs 24/7. Our Azure migration cost breakdown walks through the real numbers.
What's actually new in Windows Server 2025?
The feature most likely to matter to a small business is hotpatching, which applies most security updates without a restart. Microsoft launched Azure Arc-enabled hotpatching as a paid subscription at $1.50 per CPU core per month, billed from July 2025, then reversed course. Microsoft's documentation now states that Arc-enabled hotpatch for Windows Server 2025 is available at no extra cost.
Without it, you reboot monthly. With it, you take roughly four planned baseline restarts a year. For a server running a scheduling system or a database people use all day, that's the difference between four maintenance windows and twelve.
Beyond that: SMB over QUIC, better Active Directory performance, GPU partitioning in Hyper-V, and improved storage replica. Real improvements, but none of them is the reason a 20-person firm upgrades.
What does the upgrade cost?
Licensing is per physical core, with a minimum of 16 core licenses per server and 8 per physical processor. Microsoft sells them in 2-packs and 16-packs, plus a CAL for every user or device that touches the server.
The bigger cost is usually hardware and labor. A server that's been running since 2016 is ten years old and long out of warranty.
If you're replacing the box anyway, do it once and land on 2025. Buying new hardware to run 2022 today puts you back in this conversation before the machine is depreciated.
Budget the downtime honestly. A clean build with data migration is typically a weekend, not an evening, and the cutover is the part that runs long.
Frequently asked questions
Is Windows Server 2025 stable enough to deploy?
Yes. It released in November 2024 and has been through nearly two years of cumulative updates. The early-adopter risk has passed. Confirm your line-of-business application vendor supports it before you commit, because vendor certification lags Microsoft's release by a year or more on some products.
Can I upgrade Windows Server 2012 R2 directly to 2025?
Yes, for nonclustered systems. Microsoft lists 2012 R2 as a supported in-place upgrade source for 2025 under the four-version rule. That said, the hardware under a 2012 R2 install is usually a decade old or more, and a clean build on new hardware is the better call.
What happens if I stay on Windows Server 2016 past January 2027?
The server keeps running and stops getting security patches. In practice, that ends your cyber insurance coverage for that system, fails most compliance frameworks, and turns every new vulnerability into a permanent one. Extended Security Updates may be available for purchase, but they're a bridge, not a plan.
Do I need new CALs for Windows Server 2025?
Yes, if your current CALs are older. CALs work forward, not backward: 2025 CALs cover 2025, 2022, and 2019 servers, but 2022 CALs don't cover a 2025 server. If you're on Software Assurance, check what your agreement already entitles you to before buying anything.
Should I buy a new server or move to Azure?
Move file shares and print to Microsoft 365 first, then size what's left. A single line-of-business app usually runs cheaper on a small on-premises box than an always-on Azure VM, while seasonal or variable workloads favor the cloud. The answer changes once you've shrunk the workload, so shrink it first.
What to do next
Find out what version each of your servers is running and what applications depend on it. That inventory takes an afternoon and it decides everything else.
If you'd like a second opinion on whether the box should be replaced, upgraded, or retired, book a complimentary infrastructure assessment. We'll tell you which of your servers actually needs to exist. Our managed IT services cover the migration work if you want it handled.
Joe Laboy handles systems and infrastructure at The NetSys Group, which has delivered managed IT, cybersecurity, and cloud services since 1998. Our engineers hold degrees in electrical and computer engineering and are certified Microsoft and Cisco instructors, serving businesses across NY, NJ, CT, PA, and Southwest Florida.
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