Windows 10 stopped receiving security updates on 14 October 2025. If that date came and went while you were busy actually running your business, rather than fussing over operating systems, congratulations, you’re normal. But here’s the uncomfortable bit: normal doesn’t mean safe.
Plenty of small and medium businesses are still quietly running Windows 10 right now, in 2026, on machines that handle invoicing, customer data, payroll, the lot. Nothing’s crashed yet. Nothing’s been hacked yet. So it feels fine. That’s the trouble with outdated software though, isn’t it? It doesn’t announce the problem. It just sits there, getting weaker, until the day it very much doesn’t sit there quietly at all.
This isn’t a Microsoft marketing exercise dressed up as a warning. The risks of running outdated software in business are real, they’re measurable, and they tend to arrive all at once, in the worst possible week.
Why Windows 10’s End of Support Actually Matters
Every bit of software has a shelf life. Vendors patch it, support it, and eventually stop, because maintaining old code forever isn’t commercially sensible for anyone. Windows 10 has now hit that wall. Microsoft has moved its attention, its engineers, and crucially its security patches, over to Windows 11.
What does “end of support” actually mean in practice? No more security updates. No more bug fixes. No more help desk support from Microsoft if something goes wrong. Your computer will still switch on. It’ll still open your email and your spreadsheets. It just won’t be defended anymore. Think of it less like a car breaking down and more like your front door lock quietly stopping working while you carry on locking it out of habit.
There is an Extended Security Updates programme for businesses willing to pay for a short-term reprieve, and some larger organisations have taken that route. But it’s a sticking plaster, not a strategy, and it doesn’t last forever.
The Security Risks Nobody Budgets For
Here’s where it gets genuinely serious. Once a piece of software stops getting patches, every vulnerability discovered in it from that point on stays open. Forever. Nobody’s coming to fix it. Cybercriminals know this, and they actively hunt for businesses running unsupported systems, because it’s easier pickings than attacking something current.
Ransomware gangs don’t discriminate by business size. If anything, smaller firms are more attractive targets, because they’re less likely to have dedicated security staff watching for trouble. An unpatched Windows 10 machine sitting on your network is essentially an open window in an otherwise locked building. It only takes one.
Data breaches following on from this aren’t hypothetical either. Customer records, financial details, supplier contracts, all of it becomes exposed the moment an attacker gets a foothold through an outdated, unprotected endpoint. And once that data’s out, there’s no putting it back.
The UK’s National Cyber Security Centre publishes clear guidance on exactly this scenario. Their device security guidance on managing obsolete products sets out plainly why continuing to run unsupported software or hardware increases your exposure to attack, and why organisations should have a plan for retiring or upgrading systems before support ends, not after something’s gone wrong. It’s not scaremongering. It’s the same organisation that advises UK government departments, and they don’t tend to overstate things for fun.
Compliance and Legal Trouble You Didn’t Sign Up For
This is the part that catches business owners out, because it feels like an IT problem until suddenly it’s a legal one.
Most data protection obligations, whether that’s UK GDPR or sector-specific rules in finance, healthcare, or legal services, expect businesses to take “appropriate technical measures” to protect personal data. Running software with known, unpatched security holes is a fairly hard thing to defend as “appropriate” if a regulator ever comes asking questions after a breach. You don’t want to be the business explaining to the Information Commissioner’s Office that your defence was, essentially, “we hadn’t got round to updating it yet.”
Insurance is the other sting in the tail. Cyber insurance policies increasingly include clauses requiring supported, up-to-date software as a condition of cover. Skip that requirement, get breached, and you might discover your policy is worth precisely nothing when you actually need it. That’s not a footnote. That’s the whole point of having insurance evaporating at the worst possible moment.
Fines, legal fees, breach notification costs, potential compensation claims. None of these show up on a spreadsheet until they land, and by then it’s rather too late to do the sensible thing you were putting off.
Operational and Performance Costs: The Slow Bleed
Even setting aside hackers and regulators entirely, there’s a simpler problem. Old software is just worse to use.
Systems running unsupported operating systems tend to crash more, run slower, and increasingly refuse to play nicely with newer hardware, printers, or third-party software that’s moved on without them. Every crash is lost time. Every “have you tried turning it off and on again” moment is an employee not doing their actual job. Multiply that across a team, across a year, and it adds up to a genuinely painful chunk of lost productivity, even if no single incident feels dramatic on its own.
Then there’s support, or the lack of it. Once Windows 10 is unsupported, Microsoft’s help desk won’t touch your issue. Software vendors start dropping compatibility for older operating systems too, because why would they keep testing against something the manufacturer itself has abandoned? You end up isolated, running critical business functions on a platform that increasingly nobody wants to help you with. That’s a lonely place to be when something breaks on a Friday afternoon.
Risks of Running Outdated Software in Business: What It Actually Costs You
Strip away the technical language and the risks of running outdated software in business boil down to three things stacking on top of each other. You’re more exposed to attack. You’re more exposed to legal and regulatory consequences if that attack succeeds. And you’re bleeding time and money daily through slower, crankier systems even before anything dramatic happens.
None of these risks are exotic or unlikely. They’re the predictable, well-documented consequences of software ageing past its support date, which is exactly why bodies like the NCSC bother publishing guidance on it. This isn’t a rare edge case. It’s what happens, eventually, to every business that leaves it too late.
So What Should You Actually Do About It?
Right, enough gloom. The fix here isn’t complicated, it’s just something that needs actually doing rather than filed under “later.”
Start by finding out what you’re actually running. Not what you think you’re running, what’s genuinely on every device across your business. You’d be surprised how often that laptop in the back office nobody’s touched since 2022 is still merrily running Windows 10, connected to everything.
From there it’s a fairly straightforward path: upgrade eligible machines to Windows 11, replace the ones too old to cope (and there will be some, that’s just how hardware works), and make sure whatever comes next is properly maintained rather than left to quietly rot for another five years.
This is precisely the sort of unglamorous but essential work Your IT’s Technology & Software service handles for businesses that would rather get on with running their business than audit their own laptops. A proper assessment tells you where you actually stand, not where you assume you stand, and maps out what needs doing without the drama or the jargon. It’s the difference between fixing this on your own terms now, calmly, versus fixing it in a panic later, expensively, probably at 11pm on a Sunday.
Windows 10 isn’t going to start working again. It’s not coming back from end of support with a surprise update and a apology note. The only question left is whether you deal with that fact now, while it’s just an admin task, or later, when it’s an incident report.
