If your business is still running Windows 10 on some or all of its computers, you are not alone, and you are not in immediate danger this morning. But the clock is now running in a way it was not before. Microsoft ended mainstream support for Windows 10 on 14 October 2025, which means those machines no longer receive the free security updates that quietly protect them every month.
This guide explains, in plain terms, what that actually means for a UK SME, what your realistic options are, and the practical steps to take now so this becomes a planned project rather than an emergency.
What "end of support" really means
End of support does not mean your Windows 10 computers stop working. They will still switch on and run your software. What changes is what happens behind the scenes: Microsoft no longer issues the security patches that fix newly discovered vulnerabilities, and there is no more technical support for the operating system itself. You can read Microsoft's own confirmation on its Windows 10 support has ended page.
The risk is cumulative rather than instant. Every month that passes, attackers learn about fresh weaknesses that will never be fixed on an unsupported system. Over time, an unpatched machine becomes a steadily softer target, and that matters most on the computers holding your email, accounts, and customer data.
The honest framing: Windows 10 is not "unsafe today", it is "no longer being kept safe". For a business, that is the line worth acting on before it becomes a problem.
Why this also matters for compliance and insurance
Beyond the direct security risk, running an unsupported operating system can quietly undermine things you may rely on. Cyber Essentials certification, for example, expects the software you use to be supported and receiving updates, so unsupported machines can put certification at risk at renewal. Many cyber insurance policies ask similar questions, and some contracts with larger clients require you to keep systems patched. If any of those apply to you, Windows 10 is not just an IT question, it is a governance one.
Your realistic options
There is no single right answer for every business. In practice, most SMEs land on one of three routes, often a mix across their fleet.
1. Upgrade eligible PCs to Windows 11
For most reasonably modern computers, upgrading to Windows 11 is the cleanest long-term answer, and the upgrade itself is free if the hardware qualifies. Windows 11 has stricter hardware requirements than Windows 10, most notably a security chip called TPM 2.0, so some older machines will not be eligible. A quick audit will tell you which of your PCs can move and which cannot.
2. Replace hardware that cannot be upgraded
Some older computers simply will not meet the Windows 11 requirements, and forcing the issue is usually a false economy. If a machine is several years old, the sensible move is often to plan its replacement rather than nurse it along. Spreading these replacements over a few months keeps the cost predictable and avoids a single painful bill.
3. Buy time with Extended Security Updates (ESU)
Microsoft offers a paid Extended Security Updates programme that keeps critical security patches flowing after the deadline. For organisations it is available for up to three years, as an annual subscription whose price increases each year, so it is designed as a temporary bridge, not a permanent home. The details are on Microsoft's Extended Security Updates programme page. ESU makes sense when you have a specific machine or application that genuinely cannot move yet, but leaning on it fleet-wide usually costs more and solves less than simply planning the migration.
A practical checklist to work through now
You do not need to do everything this week. You do need a plan. Work through the following, ideally over the next month or two.
- Take an inventory. List every computer in the business and note which version of Windows each one runs. You cannot plan what you have not counted.
- Check upgrade eligibility. For each Windows 10 machine, confirm whether it meets the Windows 11 hardware requirements. This splits your fleet into "upgrade" and "replace".
- Prioritise by risk. Machines that handle finance, customer data, or remote access should move first. A rarely used back-office PC can wait a little longer.
- Check your critical software. Confirm your key line-of-business applications are supported on Windows 11 before you move. This is where nasty surprises hide.
- Back up before you change anything. A verified backup means an upgrade or a rebuild is a routine job, not a gamble.
- Set a realistic timeline and budget. Phasing replacements over a few months keeps costs predictable and avoids disruption.
How to avoid the common mistakes
The two most frequent errors we see are opposite extremes. Some businesses panic and rip everything out at once, causing needless disruption and expense. Others do nothing at all, assuming that because the computers still work, nothing has changed. The right path is the calm middle: a phased, prioritised migration where the highest-risk machines move first and the rest follow on a schedule you control.
It also pays to treat this as a chance to tidy up rather than a like-for-like swap. Moving to Windows 11 is a natural moment to review who has access to what, to make sure backups are actually working, and to confirm that multi-factor authentication is switched on across your accounts. Getting the operating system current is a good foundation, and combining it with sensible cybersecurity basics is where the real value sits.
Where a managed IT partner helps
For a small team without in-house IT, the hardest part is not the technical work, it is knowing the order to do it in and having someone own the plan. A good managed IT support partner will inventory your devices, tell you honestly which to upgrade and which to replace, check your software will keep working, and phase the whole thing so your people are never left without a working computer. With 24/7 monitoring and a proactive approach, the aim is that migrations like this are planned well ahead of the deadline, not scrambled after it. Our support team is UK-based, so you are talking to people who understand the local context rather than an overseas call centre.
The bottom line
Windows 10 will keep running, but it is no longer being kept safe, and for a business that gap only widens with time. The good news is that this is an entirely manageable project when it is planned. Count your machines, sort them into upgrade and replace, protect your most sensitive computers first, and phase the rest at a pace that suits your budget.
If you would like a hand working out where you stand, we are happy to help. Get in touch for a free, no-obligation chat via our contact page, and we will talk you through a sensible plan for your business, with no pressure and no jargon.
