Windows 10 end of support sounds like an IT problem until you look at the oldest computer in your office. Maybe it’s the one next to the printer, or the one your accountant swears she’ll never give up. It starts up fine, opens every file, and nobody has complained in months.

But unless someone paid to keep it covered, it hasn’t had a single security patch from Microsoft since October 14, 2025. There’s no warning on the screen and no pop-up. The computer feels exactly the same while the gaps in it quietly grow.

At ZIA Networks, we find machines like this on business networks all the time. It’s rarely carelessness. Nothing tells you when it happens, so it’s easy to miss.

So, is an unsupported computer safe for business use? No. Every new security flaw stays open for good, and attackers actively look for the machines that never got fixed.

The good news is you have two clear options: pay for Microsoft’s temporary Extended Security Updates, or move to Windows 11. This guide shows you how each one works, so you can choose with a clear head.

What Does Windows 10 End of Support Mean?

Windows 10 end of support means Microsoft no longer provides free security patches, bug fixes, or technical help for Windows 10. The operating system still runs, but newly found vulnerabilities go unpatched unless you pay for Extended Security Updates. Support ended on October 14, 2025.

Think of it like a building whose fire inspections have stopped. The doors still open and the lights still work. But nobody is checking the wiring anymore, and if something goes wrong, nobody is coming.

Microsoft’s lifecycle pages call this milestone Windows 10 end of life. The final version, 22H2, is the last Windows 10 release that will ever ship.

What stops, and what keeps working

Your computers did not switch off on that date. Most of what you rely on still functions. What changed is the safety net underneath.

That last row catches people off guard. Microsoft is continuing security updates for Microsoft 365 Apps on Windows 10 until October 10, 2028. That protects Word and Excel. It does not protect the operating system underneath them. 

Is an Unsupported Computer Still Safe to Use?

A computer without any kind of support is not fit to be used in a business environment, as the attacker would know of such vulnerabilities beforehand. This means that when you do not update the computer monthly, you are exposing yourself to more security risks.

This is how it works. As soon as Microsoft resolves a vulnerability, it publishes information about it.  

On a supported machine, that is fine, because the patch is already installed. On an unsupported one, the same notes become a to-do list for attackers.

Windows 10 security risks that hit small businesses hardest

It is not necessary for you to be either a bank or a hospital to be an attack victim. Automated programs search the internet for vulnerable networks on a continuous basis without considering your size. The following are the important Windows 10 security threats for a business that is growing:

• Entry point for ransomware. The presence of unpatched vulnerabilities is a typical method that ransomware uses to gain access to a system and subsequently to infect an entire network.
• Compromised credentials. One infected computer can reveal passwords, mail sessions, and credentials to cloud-based software.
• Exposure of the weakest link. Your level of security depends on your oldest computer. That’s why the computer that is often overlooked in your network could be dangerous.
• Silent compromise. Many attacks run for weeks before anyone notices. An unpatched PC gives them more room to hide.

The “slow leak” effect

Here is a perspective most guides skip. The danger of an unsupported system is not a cliff edge. It is a slow leak.

On day one after the cutoff, a Windows 10 PC is nearly as safe as it was the day before. But every month, another batch of vulnerabilities is discovered and goes unfixed. After a year, the gap is large. After three, it is enormous.

That is why “it has been fine so far” is a poor test. A PC with no patches for twelve months is a very different machine from one that lost support last week.

Where Does Your Business Stand Today?

Your situation depends on one question: is each of your Windows 10 PCs enrolled in Extended Security Updates, or not?

Microsoft provided an ESU bridge for those who cannot transition all at once. This service is named ESU, and the deadlines related to it should be noted.

Extended security updates for Windows 10: what you actually get

Extended Security Updates (ESU) are paid, per-device subscriptions that provide critical and important security patches after the end of support. No additional features or technical support are included in ESU. Business organizations may obtain up to three years of ESU service until October 2028.

The price climbs sharply each year. Commercial pricing starts at $61 per device and doubles every year for three years. Here is how the schedule looks:  

Microsoft’s schedule runs commercial coverage through October 13, 2026 for Year 1, October 12, 2027 for Year 2, and October 10, 2028 for Year 3. 

The rule that surprises latecomers

If you did not buy ESU last year, read this carefully. Commercial customers cannot buy part of a year, and coverage is cumulative, so a business that first buys during Year 2 must also pay for Year 1

That means a business enrolling a PC today pays $61 plus $122, which is $183 per device, just to get back to even. There is no discount for the months you already missed.

A worked example

Take a 25-computer office. This is an illustration, not a quote:

• Joining ESU today: 25 × $183 = $4,575 for coverage through October 2027
• Staying through Year 3: add 25 × $244 = $6,100, bringing the total to $10,675
• Result: you have spent over ten thousand dollars and still own the same aging computers

ESU is rent. It buys time. It does not build any equity in your technology.

Two things that don’t renew themselves

ESU does not auto-renew. If a device is not enrolled for the current year, updates simply stop. There is no warning banner, so you have to track enrollment yourself.

There is also a cloud route. Windows 10 PCs that connect to Windows 365 receive Extended Security Updates at no extra charge. It suits some teams, but it changes how people work, so test it before committing.  

To keep the picture honest: the Windows 10 end-of-support milestone did not remove your options. It put a price on delay.

The Business Risks Beyond Hackers

Most articles stop at cybersecurity. But for a business, the consequences spread wider than a breach.

Compliance and audit exposure

Many regulations and frameworks expect you to run supported software. These include PCI DSS for card payments, HIPAA for health data, and a range of client security questionnaires.

In the event that the auditor discovers that your network has unsupported operating systems, there is every likelihood that he will signal his concern about it, and this might bring about delays in the contracts or even deadlines.

Cyber insurance headaches

Insurance companies are more stringent about basic security. Using outdated operating systems can increase rates, exclude you from insurance, or make claims after an incident difficult.

Review the language in your policy before any problem occurs. Verify with your broker whether outdated operating systems impact your coverage.

Software and vendor compatibility

Eventually, software vendors will discontinue compatibility testing for outdated operating systems. It is possible that your accounting software, customer relationship management software, or any other specialized application might continue to work until a new version is released, and then fail afterwards.

At that point, the support staff at the vendors will recommend that you upgrade before anything else. You lose time just when you need it most.

Hardware drivers and peripherals

New printers, scanners, and security devices increasingly ship with drivers built only for current Windows versions. An older PC can become the reason a new purchase will not work.

The productivity tax

Aging machines are slow. Shaving a few minutes a day off every employee adds up quickly across a year, and that cost never shows up as a line item.

Can Your Computers Run Windows 11?

The cleanest long-term solution would be to go for Windows 11. However, this isn’t possible on all machines, and that’s where the problem comes in.

To install Windows 11 on your system, you must have a 64-bit CPU with 4 GB RAM, 64 GB storage, an updated UEFI firmware with Secure Boot capability, and TPM 2.0. All enterprise computers that have been purchased in the last five or six years have met these requirements.

Windows 11 minimum requirements at a glance

In rough terms, the processor list is the usual dealbreaker. Machines older than about 2018 often fall short, though there are exceptions in both directions.

How to check quickly

Use Microsoft’s PC Health Check app on a single machine to see its status. Your IT department or vendor can conduct an asset audit that will give an inventory of all the devices present in the entire office at once.

Do not depend on the age of the computer only. The five-year-old computer will be fine, but the three-year-old computer may not be.

Sort every device into three groups

Once you have results, place each PC into one of these buckets:

1. Ready now. It passes every check and can be upgraded in place.
2. Fixable. It fails on something small, like a disabled TPM setting or low RAM, that a technician can resolve.
3. Replace. The processor or chip cannot meet requirements, and spending money on it is poor value.

This simple sort turns a vague worry into a budget and a schedule.

Planning a Windows 11 Upgrade for Business

Windows 11 migration in business is not only an installation. If done right, it is a short-term project divided into clear phases. If not, it is a whole week of downtime and disgruntled employees.

Why sometimes in-place upgrades should not be used

A ten-year-old Windows installation has been accumulating many unused configurations, applications, and potential issues through the years. On old or heavily customized computers, a fresh installation is usually faster and more stable.

Your IT provider will be able to guide you in choosing for each machine. The fresh and new computers will upgrade easily in place.

An estimated timeline of Windows 11 migration

A realistic Windows 11 migration process of a small or mid-sized business looks something like that:

1–2 Weeks: Discover and decide

• Inventory every device, including laptops, remote workers’ machines, and shared PCs
• Run compatibility checks and sort devices into the three groups above
• List business-critical applications and confirm each works on Windows 11

3–4 Weeks: Pilot

• Upgrade a small test group across different departments
• Collect feedback on speed, app behavior, and printer or peripheral issues
• Fix problems before they affect everyone

5–8 Weeks: Roll out

• Migrate in waves, starting with the lowest-risk teams
• Schedule upgrades outside peak hours
• Back up data before touching any device

Ongoing: Close the loop

• Retire or securely wipe replaced hardware
• Update your asset register and warranty records
• Confirm any leftover Windows 10 PCs are enrolled in ESU, or isolated, until they are gone

Protect your people, not just your PCs

Changing an operating system changes how people work, from the Start menu layout to how settings are found. It helps to give a short brief and a one-page cheat sheet to avoid “Where did it go?” tickets.

Provide notice to your employees and tell them why this is going on. That small effort saves the most time.

ESU, Upgrade, or Replace: Which Path Fits?

It all depends on which one suits you. What’s most appropriate will depend on the vehicles you have at hand, your budget, and your schedule. Here is a comparison to help you choose:

How to read this table

ESU makes sense when a specific device cannot move yet. Examples include a machine tied to a legacy application, or a PC waiting on a vendor update.

It makes far less sense as a blanket strategy for your whole fleet. The price doubling each year is designed to push you toward a decision.

A mixed strategy is recommended in most cases. Enhance those items that fit; replace those that do not; apply ESU to those items only that need it.

Common Mistakes to Avoid

After watching businesses handle this transition, the same errors keep appearing.

• Assuming “no news” means “no problem.” Unsupported systems fail quietly. You will not get an alert.
• Forgetting the hidden devices. Home-office laptops, reception PCs, and machines running a single legacy tool often get missed.
• Buying ESU without a plan. Paying for a bridge is fine. Paying for a bridge to nowhere is not.
• Skipping the backup. Always back up before upgrading or replacing anything.
• Leaving old PCs on the main network. If a Windows 10 device must stay unpatched, isolate it from systems holding sensitive data.
• Waiting for a perfect moment. There is no quiet month. The cost of delay is real, and it rises each year.

FAQs

1. Is it still feasible to run Windows 10 without updates?

Yes, the system will remain operational, but there won’t be any security updates provided. In a business setting, that increases the risk of attacks and makes one non-compliant with certain requirements.

2. When did Windows 10 end of support happen?

The end of support date of Windows 10 was October 14, 2025. From that moment on, only organizations enrolled in the paid ESU program had their systems updated.

3. What is the price of Windows 10 ESU for enterprise?

Commercial ESU costs $61 per device for Year 1, $122 for Year 2, and $244 for Year 3. Coverage is cumulative, so enrolling now means paying for earlier years too.

4. How long can I use Extended Security Updates?

Businesses can purchase up to three years, with the final coverage period ending October 10, 2028. After that date, there is no further extension planned.

5. Will Windows 11 run on my old computer?

Possibly. It needs a supported processor, TPM 2.0, Secure Boot, 4 GB of RAM, and 64 GB of storage. Many PCs from before roughly 2018 do not qualify.

6. Is it safe to use an unsupported computer with antivirus software?

Antivirus helps, but it cannot fix flaws in the operating system itself. It is a useful extra layer, not a replacement for patches.

7. What is the cheapest way to stay secure?

Windows 11 proves to be the least expensive choice for upgrading PCs that fit the criteria, since it does not carry any annual cost. ESU is cheaper only as a short, temporary bridge. 

Your Next Steps: A Quick Action Summary

If you take one thing from this guide, make it this: unsupported does not mean unusable, but it does mean unprotected. The longer you wait, the more it costs, in money and in risk.

Here is your practical checklist:

1. Audit every computer you own and note its Windows version
2. Test each device against Windows 11 requirements
3. Sort devices into ready, fixable, and replace
4. Enroll any devices that must stay on Windows 10 in ESU, and isolate the rest
5. Schedule your migration in waves, starting with a pilot group
6. Review your insurance and compliance obligations while you plan

The Windows 10 end of support deadline is behind you, but you still have choices. You can still move on your own terms instead of waiting for an incident to force the decision.

Ready to Get Your Business Protected?

We at ZIA Networks ensure that businesses understand where they are, from inventorying devices to preparing a detailed, costed migration strategy. We take care of everything from assessing to planning and deploying, allowing your employees to continue working as your technology evolves.

Book a free Windows readiness assessment with ZIA Networks today. We’ll tell you which PCs are safe, which need action, and what it will realistically cost, with no jargon and no pressure.