Just two weeks left until yet another one of Microsoft’s end-of-support (EOS) milestones, and with that comes the usual scramble: what to do with devices still running Windows 10, pre-2020s Office builds, and on-prem Exchange? Security, licensing compliance, new software compatibility and service availability cannot be neglected just because your upgrade plan is coming together at a slower pace than expected. If your organization keeps running any given software after EOS, you need a mitigation path to ensure potential vulnerabilities remain addressed – either from Microsoft or a third-party patching solution.
What’s actually affected?
The list of products is quite significant and affects a huge number of users, both businesses and consumers – the most popular of them being:
- Windows 10 – all common editions (Home, Pro, Enterprise, Education)
- Exchange Server 2016/2019 – on-premise perpetual deployments
- Office 2016/2019 – all common, on-premise editions (Home and Student, Home and Business, Standard, Professional, Professional Plus)
Note: A full list of products reaching End of Support this year can be found here.
Each of the 3 product lines mentioned above carries a different resolution in the current situation – let’s break them down.
Longer support with Extended Security Updates (ESU)
What exactly is ESU?
Extended Security Updates (ESU) is a paid service by Microsoft which provides the option to prolong the use and lifecycle of certain software products past the end of their support date. ESU is not designed to be a permanent solution but a short-term bridge meant to give users a little more time to upgrade to a supported software product.
Windows 10
- Scope & licensing: available to organizations for devices running Windows 10 Pro or Enterprise, version 22H2 with recent updates. It can be licensed per device (or per user in some agreements) via Microsoft’s commercial channels.
- Duration: up to 3 years – a finite runway of critical and important security fixes beyond EOS; feature updates and general support are not included.
- Where to purchase: through Microsoft’s volume-licensing ecosystem or approved CSP partners, such as Forscope.
- Forward path: after having made use of ESU, or potentially Windows 10 Enterprise LTSC, the next step is naturally Windows 11 – it is considered that these 3 additional years will give most companies the time necessary to invest in devices that meet the necessary hardware requirements that their current infrastructure may be lacking.
Whats is Windows 10 Enterprise LTSC?
Microsoft’s Windows 10 Enterprise LTSC (Long-Term Servicing Channel) is a standalone operating system similar in most of its functionality and hardware requirements to mainstream Windows 10 editions but characterized by some limitations in features and feature updates. These limitations however are the reason for its higher stability and security, and longer support period. The distribution channel that it comes from (LTSC) is focused on providing durable and secure software to facilities with critical infrastructure (e.g. hospitals, airports etc). Windows 10 Enterprise LTSC 2019 specifically can deliver up to four more years of supported operation without the need to spend funds on ESU or any other subscription – the only purchase is of the perpetual license itself.
Exchange Server 2016/2019
- Scope & licensing: targeted primarily at selected large enterprises with on-prem dependencies that can’t be unwound overnight.
- Duration: 6 months only – until April 14, 2026. Microsoft has firmly stated that there will be no extensions after that point.
- Where to purchase: very limited access – only via Microsoft’s designated channels reserved for selected large enterprises.
- Forward path: the replacement for the last perpetual Exchange Server, version 2019, is Exchange Server Subscription Edition (SE) – it’s the only option from Microsoft for organizations that must keep email servers on-prem and want an in-support future. Alternatively, business customers can also choose from cloud-based Exchange Online options.
Office 2016/2019
Third-party help: the 0patch path
If Microsoft’s ESU doesn’t fit your size, budget, or software mix, 0patch is a reliable, occasionally even more advanced substitute:
- Scope: Windows 10 and Office 2016/2019; Exchange is unfortunately not on the menu.
- How it works: tiny, in-memory “micro-patches” applied instantly; deployed via a lightweight agent;
- Why pick it:
- Rapid reaction to high-risk flaws and near-instant deployment.
- Lower cost than official ESU in many scenarios.
- Responsive team that stays in close contact with customers.
- Use cases: SMEs, cost-conscious organizations, and anyone needing a gap-fill between EOS and a planned migration window.
How does 0patch compare to Microsoft’s ESU and LTSC programs price-wise?
Let’s compare three specific products from each category to gain a clearer understanding by evaluating them in a simple scenario involving 50 users over a three-year period.
Windows 10 ESU vs Windows 10 LTSC vs 0patch Enterprise (50 users)
| Solution | Total Cost (3 years) | Savings compared to ESU | % Savings |
|---|---|---|---|
|
Windows 10 ESU 3 years |
22 800.00 € |
– |
– |
|
0patch Enterprise |
1 747.50 € |
17 557.50 € |
77% |
|
Windows 10 Enterprise LTSC 2019 |
1 100.00 € |
21 700.00 € |
95% |
The outcome is fairly straightforward: justifying the choice of ESU to your CFO may prove difficult. However, in reality, the situation is usually more complex than the example presented. Organizations often have a mix of power users and general users, each with significantly different software and security needs. Additionally, the types and ages of devices, systems, and networks can vary considerably. A one-size-fits-all approach is seldom the most effective strategy.
Main takeaways and recommendations
- Prolong and stabilize your operating system setup with Windows LTSC – continue using Windows 10 while simultaneously reducing update fatigue and UI clutter, and tightening security. Mind the lack of certain components (Copilot, Widgets, Microsoft Store etc) and the potential for incompatibility with newer software and hardware.
- Harden Windows 10 post-EOS with ESU, or 0patch if ESU isn’t financially feasible for your organization.
- Extend security for Office 2016/2019 with 0patch and save on unnecessary spending on newer Office versions with unneeded features, or expensive Microsoft 365 subscriptions.
- Don’t overstretch your migration deadline from on-prem Exchange to SE – plan your move to the subscription-based edition for on-premise server environments (Exchange Subscription Edition), or consider moving to Microsoft cloud infrastructure (Exchange Online). Make sure it is based on an explicit timeline with coexistence and rollback defined.
- Inventory and segment:
- Plan the migration: Build a phased roadmap for replacing, upgrading or keeping non-eligible hardware before EOS;
- Assess your current inventory and segment devices to eligible and non-eligible for Windows 11;
- Determine application compatibility: Identify applications that are not yet Windows 11-ready and plan mitigation strategies (upgrades, replacements, additional patches and support plans);
- Prioritize business-critical systems;
- Virtualize where necessary: Consider moving workloads that must remain on Windows 10 into a controlled virtual environment (VDI) with strict monitoring;
- Prepare backup and recovery fallbacks: Ensure EOS devices that remain in use have reliable, tested backups in case of compromise.
The bottom line
October’s 2025 EOS isn’t a headline to ignore. Unpatched endpoints become everyone’s problem – first yours, then your auditors’, and eventually your customers’. Whether you buy ESU, deploy 0patch, or purchase still supported Windows 10 LTSC editions, the critical move is to act now: bridge the gap between supported and legacy software in your environments and prepare your migration path. Don’t wait for an incident to occur!
How to take the next step? Let us help you!
If you require assistance sizing ESU vs. 0patch, mapping LTSC candidates, or retiring an Exchange Server infrastructure, reach out to us. Our experts will analyze your current infrastructure, segment it by devices and license types, and tailor licensing and transition plans suited to your environment and budget.
