TL;DR:

  • Microsoft ended free security updates for Windows 10 on 14 October 2025. Unpatched vulnerabilities will no longer be fixed.
  • Extended Security Updates (ESU) are available for £25–30 per PC per year — a short-term option while you plan migration
  • Windows 11’s hardware requirements exclude some older PCs, but many machines from 2018 onwards can upgrade for free

Microsoft’s Windows 10 reached end of life on 14 October 2025. That date passed nine months ago, and in the rush of running a business, it may not have landed on your radar. But if your computers are still running Windows 10 — and a very large number of UK small business machines are — you should understand what’s changed.

The short version: your computers are no longer receiving security patches. Any vulnerability that Microsoft discovers (or that attackers exploit) in Windows 10 after that date will not be fixed for you. Your antivirus can still catch known malware, but the operating system itself is no longer getting the fixes that close the doors attackers use to get in.

This is a real risk. Not an abstract one.

Why This Matters More Than You Might Think

When software goes out of support, attackers pay attention. They know that vulnerabilities found after the end-of-life date will never be fixed for those users. Some criminal groups specifically search for and collect vulnerabilities to use against organisations running unsupported software, knowing the window of exploitation is indefinite.

The most well-known example of this dynamic was WannaCry in 2017, which devastated businesses and the NHS by exploiting Windows XP systems that Microsoft had stopped supporting years earlier. Microsoft actually broke from policy and issued an emergency patch for XP in that case — but that’s an exceptional response to an exceptional crisis, not standard practice.

Windows 10 is a much more widely deployed operating system than XP was at end-of-life. The scale of the unsupported estate makes it an attractive target.

What Microsoft Is Offering: Extended Security Updates

Microsoft introduced Extended Security Updates (ESU) for Windows 10, available to buy individually or through Microsoft 365 subscriptions. This gives you continued security patches beyond the October 2025 deadline — but with an important structure:

  • Year 1 (to October 2026): Available now. Approximately £25–30 per device per year if purchased individually.
  • Year 2 (to October 2027): Will be double Year 1 pricing.
  • Year 3 (to October 2028): Triple Year 1 pricing.

Microsoft’s pricing is designed to incentivise migration rather than extended use of Windows 10. The price increases make ESU expensive as a long-term solution, but it buys you time if you can’t upgrade immediately.

If you use Microsoft 365 Business Premium or have an active Microsoft 365 subscription covering your devices, check whether ESU is included — Microsoft made ESU free for the first year for some Microsoft 365 subscribers in an attempt to reduce the overall unsupported estate.

Are Your Computers Eligible for Windows 11?

Windows 11 has stricter hardware requirements than Windows 10. The key requirement is TPM 2.0 (Trusted Platform Module) and a processor from Intel’s 8th generation or later (Coffee Lake, 2017 onwards) or AMD Ryzen 2000 series or later.

A significant proportion of business laptops and desktops purchased after 2018 can upgrade to Windows 11 at no cost. The upgrade is a free download. To check:

  1. Download the PC Health Check app from Microsoft’s website
  2. Run it on each computer — it will tell you whether the machine is compatible and, if not, which specific requirement it fails

If the machine passes, upgrading is the right move: Windows 11 is actively supported until at least 2031, you’re not paying for ESU, and you get security improvements that Windows 10 doesn’t have (including better built-in phishing protection and tighter app isolation).

What About Machines That Can’t Upgrade?

If a machine fails the Windows 11 compatibility check, you have three options:

Replace the hardware. Refurbished business laptops from 2019–2021 are available from reputable UK suppliers for £200–350 with Windows 11 pre-installed. If a machine can’t run Windows 11, it’s typically five or more years old. For a business-critical machine, replacement is often the right call.

Pay for Extended Security Updates. If you need more time — perhaps the machine runs specialist software that requires testing before a migration — ESU buys you one to three more years of patches. Not cheap, but cheaper than a breach.

Isolate the machine. If a Windows 10 machine runs a single application (a dedicated till, a piece of production equipment, a specific accounting package) and doesn’t browse the internet or open emails, you can significantly reduce its risk by isolating it from general network traffic. Put it on its own VLAN or physically separate it from your main network. It’s still unpatched, but an isolated machine is a much harder target. Talk to your IT support about whether this is feasible.

The Practical Checklist for Right Now

  1. Find out what’s running Windows 10 in your business. IT support can generate a list, or you can check by going to Settings > System > About on each machine.

  2. Run the PC Health Check on each Windows 10 machine to know which ones can upgrade for free.

  3. Upgrade compatible machines now. It’s free, takes 1–2 hours, and solves the problem. Schedule it for a slow period.

  4. For incompatible machines, decide: replace, buy ESU, or isolate. Get quotes for refurbished hardware — they may be more affordable than you expect.

  5. Talk to your IT provider or MSP if you have one. ESU can sometimes be purchased at better rates through Microsoft partners. Ask whether it’s already included in your existing Microsoft 365 subscription.

  6. Make sure backups are current. Running on unsupported software increases the risk of ransomware or data loss. Good backups are your fallback if something goes wrong before you complete the upgrade.

The end-of-life date already passed. Every month of delay on an unpatched system is a month of elevated risk. The good news: for many businesses, the fix is a free operating system upgrade on hardware you already own.