Windows 10 support officially ends today – and millions of PCs locked out of ‘security crisis’

In the modern era, each version of Windows follows a 10-year support lifecycle. This means that almost every Windows 10 edition – Home, Pro, Pro Workstation, Enterprise, and Education – reached its support end date of October 14, 2025. (For more information on how that date is calculated, see “When will Microsoft end support for your version of Windows or Office?”)

So, what happens now that the official end-of-support deadline has passed? Nothing. In reality, nothing happened on that date. PCs running Windows 10 will continue to work as they always have, and they will continue to do so indefinitely.

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However, those PCs no longer receive security fixes via Windows Update unless their owners sign up for an Extended Security Updates (ESU) subscription. On Windows 10 PCs without ESU membership, any newly discovered security flaws will remain intact, making those PCs more vulnerable to online attacks.

The only exception to this cutoff date applies to PCs running Windows 10 Enterprise Long Term Servicing Edition, which have support end dates ranging from October 2026 to January 2029. But those editions are specifically for enterprise customers with volume license agreements and are not relevant to mainstream PCs.

No one outside Redmond knows how many PCs are still running Windows 10 today. Microsoft can probably make a solid estimate based on its own telemetry, but the rest of us are forced to guess based on fragmented third-party metrics.

The most widely cited measurement is from the monthly “market share” reports published by Statcounter Global Stats. Unfortunately, those metrics have always been unreliable and inconsistent, but starting in May 2025 they became completely unreliable. (If you believe the StatCounter numbers for September 2025, hundreds of millions of PCs were downgraded to Windows 7 over the summer. LOL, that didn’t happen.)

This is what the StatCounter numbers looked like in April 2025.

There is a large population of people who can’t or won’t upgrade.

• Who are not eligible for automatic upgradesSome people have older hardware that doesn’t meet the minimum hardware compatibility standards for Windows 11. Basically, this means any PC that was designed in 2018 or earlier. Note that this category includes many budget PCs that used older designs and unsupported CPUs but were sold as new in 2019 and 2020.
• Corporate PCs that are standardized on Windows 10. A large number of enterprise IT managers are unwilling to undergo a wholesale Windows 11 migration. Many of them will use the normal upgrade cycle to perform that migration over time, and they will have the option to pay for Windows 10 upgrades for up to three years after the support end date.
• Windows 10 Diehard. From my time spent reading support forums, I know there is a large population of longtime Windows users who are unhappy with the changes in Windows 11. Some of them will upgrade reluctantly, but others will not.

Microsoft and its OEM partners would like owners of those devices to throw them in the landfill and buy a new PC running Windows 11. However, my experience with PC owners, especially older ones on a fixed income, is that they will use those devices until they stop working. Those PCs will sit idly by for a cyberattack like WannaCry, which was brutally effective against large populations of Windows 7 PCs that were still in use three years after its support ended.

That incident was a PR nightmare for Microsoft, and its recurrence would be even more devastating to the company’s reputation. Enterprise customers will likely take advantage of payment options to extend support for Windows 10 to three years. But consumers are already on their own and in a year they will be completely abandoned.

Brad LaPorte, a former Gartner analyst who now works for an enterprise security firm MorphisecSays the end-of-support deadline is a “security cliff”. He says, “Every month after October 2025, unpatched devices will become easy targets for ransomware and zero-day exploits. The harsh reality is that attackers are already in position.”

Luis Corones, a security evangelist at security firm Avast, says that “unpatched Windows and driver bugs become long-lived entry points.” And even if those vulnerabilities aren’t directly exploited, he adds, the end-of-support deadline is an opportunity for scammers. “People may see fake pop-ups, upgrade offers or even receive phone calls pretending to be from Microsoft.”

We are in uncharted territory.