If your business still has PCs running Windows 10, next Tuesday matters. On 13 October 2026, the next Windows 10 end of support milestone arrives: year one of Microsoft’s paid Extended Security Updates (ESU) programme for businesses comes to an end.
After that date, any business PC that isn’t renewed onto ESU year two – or upgraded to Windows 11 – stops receiving security patches. New vulnerabilities will be found, and they won’t be fixed.
A quick recap
Understanding Windows 10 End of Support
Mainstream support for Windows 10 ended in October 2025. Since then, Microsoft has offered ESU as a paid safety net, giving businesses up to three extra years of critical security updates while they move to Windows 11.
For business devices, the timeline looks like this:
| ESU year | Covers until |
|---|---|
| Year 1 | 13 October 2026 |
| Year 2 | 12 October 2027 |
| Year 3 (final) | 10 October 2028 |
Two things catch people out. First, the years are cumulative – if you missed year one, you have to pay for it to join year two. Second, the price goes up each year, so staying on Windows 10 gets more expensive the longer you leave it.
“But I read it was extended to 2027?”
You may have seen headlines in June saying Microsoft extended Windows 10 updates to 2027. That extension applies to personal, home-use PCs only. Devices joined to a business domain, Microsoft Entra ID or a device management system (like Intune) are excluded. If your PCs are managed as business devices, the business ESU dates above are the ones that apply.
Why an unpatched PC is a business risk
- Cyber attacks: Criminals actively target out-of-date systems because the weaknesses are public and the fixes will never arrive.
- Cyber Essentials: Unsupported operating systems fail Cyber Essentials, which many public sector and supply-chain contracts now require.
- Insurance: Many cyber insurance policies expect supported, patched systems. An unsupported PC can weaken a claim.
- GDPR: If a breach exposes customer data, running unsupported software is hard to defend to the ICO.
- Software support: Microsoft 365 apps and other business software are gradually dropping Windows 10 support too.
What to do this week
- Find out what you’ve got. List every PC still on Windows 10, including that one in the back office that only runs the accounts package.
- Check if it can run Windows 11. Many PCs from 2018 onwards can upgrade for free. Older machines often can’t, because of hardware requirements.
- Decide: upgrade, replace or renew. Upgrade compatible PCs to Windows 11. Budget to replace older ones. Use ESU year two only as a short-term bridge for machines you can’t move yet.
- Back up before you upgrade. Make sure files, emails and line-of-business data are safely backed up first.
- Plan, don’t panic. A staged rollout over a few weeks causes far less disruption than a last-minute rush.
How E-telegence can help
Our managed IT support team helps businesses across Falkirk, Stirling, Glasgow, Edinburgh and Central Scotland with exactly this. We can audit your devices, tell you which PCs can upgrade and which need replacing, handle the Windows 11 rollout, and keep everything patched afterwards.
Our managed IT plans start from £20 per user per month and include proactive patching and monitoring, so you never have to worry about deadlines like this again.
Not sure where you stand? Get in touch for a free Windows 10 health check.
Sources: O365HQ – Windows 10 ESU year one ends October 2026; TechRepublic – Microsoft extends Windows 10 security updates to 2027
