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Your PC displays a warning message, or you have read somewhere that Windows 10 “no longer exists.” Nothing stopped overnight, but something has indeed changed. This article explains what end of support actually means, the dates published by Microsoft, and the three options that are genuinely available to you.

What “end of support” actually changes

The first thing to understand is that an operating system reaching end of support does not deactivate it. Your computer starts, your software opens, and your files remain intact. There is no countdown that locks the machine.

What stops is maintenance. Microsoft will no longer publish the following for Windows 10:

• monthly security fixes;
• reliability and quality fixes;
• new features;
• technical support for the system.

The distinction matters. An uncorrected display bug is annoying. An unpatched security vulnerability is different: vulnerabilities discovered after support ends are publicly documented, and they remain open indefinitely on uncovered machines. The risk does not increase all at once; it grows month after month as new vulnerabilities are disclosed without ever being patched.

There is also a knock-on effect. Third-party vendors (browsers, antivirus software, business suites, and device manufacturers) tend to align their own schedules with that of the operating system vendor, but each makes its own decisions and none is obligated to do so. They therefore do not all stop at the same time, and compatibility gradually deteriorates rather than disappearing all at once. Check announcements from your critical software vendors rather than making assumptions.

The official timeline

These are the dates published by Microsoft. They may be adjusted (the consumer ESU date has already been postponed once), so always check Microsoft's published lifecycle before basing a business decision on it.

A word about this last line, which is often misunderstood: Microsoft continues to secure Microsoft 365 applications for a few years on Windows 10, but the underlying system itself is no longer maintained. An up-to-date office suite installed on a system that is not up to date does not protect you.

Check whether your PC can upgrade to Windows 11

Before making any decision, you need to know which category your machine falls into. Three checks are enough, and they take five minutes.

1. The PC Health Check app

This is Microsoft's official tool (PC Health Check). It gives you a clear verdict and, if you are refused, indicates which criterion is blocking you. It is the most reliable starting point.

2. Windows Update

Open Settings > Update & Security > Windows Update. If your PC is eligible, the upgrade to Windows 11 is generally offered there directly.

3. System tools

To check for yourself, without installing anything:

• Windows + R then winver: displays your version of Windows 10. Make a note of this number; it matters for what follows.
• Windows + R then msinfo32: the “BIOS Mode” line must indicate UEFI, and “Secure Boot State” must be enabled.
• Windows + R then tpm.msc: displays the presence and version of the TPM module.

The TPM and processor requirements

Microsoft publishes a minimum configuration for Windows 11:

Two criteria disqualify almost all rejected machines.

TPM 2.0. This is the most common unpleasant surprise, and often a false alarm. Many motherboards have it but ship with it disabled in the BIOS. Look in the settings for an option called fTPM (AMD platforms), PTT or Intel Platform Trust Technology (Intel platforms), or simply “TPM Device”: the name varies from one motherboard manufacturer to another. Enabling it is sometimes enough to unlock a machine that seemed doomed. While you are there, check that Secure Boot is enabled.

The processor. This is the most prohibitive criterion, because it cannot be bypassed through a setting. Microsoft maintains an explicit list of supported processors; in practice, generations that are too old are excluded even when they remain perfectly usable day to day. Check the official list for your exact model rather than relying on a general rule; exceptions exist within the same processor family.

Workarounds for installing Windows 11 on unsupported hardware are circulating. Microsoft states that these installations may not receive updates and fall outside the supported scope. On a serious work computer, this is not a reasonable option.

Migrating to Windows 11

If your PC is eligible, this is the simplest route, and upgrading from an activated Windows 10 is free through Microsoft. One prerequisite: your machine must be up to date with Windows 10 version 22H2, the latest released version. If you are still on an earlier version, update first through Windows Update.

In order:

• Back up everything first. An upgrade goes smoothly in the vast majority of cases. “The vast majority” does not mean “always.” Copy your documents to an external drive or the cloud.
• Review your business software. Old peripherals (scanners, professional printers, industrial equipment) are the main cause of problems. Check that Windows 11 drivers are available beforehand, not afterward.
• Start the upgrade through Windows Update, or with the Windows 11 Installation Assistant downloaded from Microsoft's website.
• Set aside some time. In my experience, allow around an hour per computer in general, and more on older hardware or with a slow connection.

Do you need to buy a Windows 11 license?

Let's be clear, because this is the question that comes up most often: if your Windows 10 is properly activated and your PC is eligible, the upgrade preserves your activation. You don't need to buy anything.

Second misconception to dispel: changing drives does not cancel your activation. A clean installation on a new SSD in the same machine will reactivate automatically. When prompted for a product key, choose “I don't have a product key,” then, if necessary, select the reactivation option “I'm reinstalling Windows on this device.” Again, no purchase is required.

A license actually becomes necessary in other situations:

• your current Windows 10 is not activated;
• you are changing the motherboard or building an entirely new machine;
• you have the Home edition and need Professional features: BitLocker, Remote Desktop host, Hyper-V, domain joining, and group policies;
• you are equipping several PCs that did not have individual licenses.

In these cases only, a Windows 11 Professional license for 3 PCs at €29.99 covers three PCs, or less than €10 per machine. The key arrives by email within minutes, and the invoice includes VAT. You will find all editions in the Windows 11 collection.

Staying on Windows 10 and the risks

Staying is a defensible choice in some situations. You simply need to do it with your eyes open.

The ESU (Extended Security Updates) program extends critical and important security updates beyond the end of support. It comes in two distinct versions, and confusing the two can be costly.

Consumer ESU. Enrollment is done through Windows Update, using a Microsoft account with administrator-level access, and coverage runs until October 12, 2027. Points to know:

• The PC must be running Windows 10 version 22H2 (Home, Pro, Pro Education, or Workstations) and be up to date.
• Once enrolled, the same Microsoft account covers up to 10 devices.
• Several enrollment methods coexist, including a free option; they have changed over time and differ by region. Check which ones apply in France on Microsoft's consumer ESU page.
• Excluded are PCs joined to an Active Directory domain, those managed by an MDM solution, and those in kiosk mode. This is the point that traps small organizations: a “managed” desktop PC cannot use this program.

Commercial ESU. It is subscribed to annually through Microsoft's volume licensing programs, at a per-device price that doubles each consecutive year, for a maximum of three years. This is deliberately prohibitive: the program is designed as a transition bridge, not as a lasting solution.

In both cases, ESU provides only security updates. No new features, no reliability fixes, and no general technical support.

Without ESU, a Windows 10 device remains acceptable in only one type of scenario: an isolated, offline, or strictly segmented machine dedicated to legacy software that runs nowhere else. A machine tool, a measurement bench, or an offline point-of-sale terminal. As soon as a device accesses the web or receives emails, the balance clearly tips the other way.

There is one narrow but real scenario: a device that is not eligible for Windows 11, covered by ESU, and needs to be cleanly reinstalled before the transition. A Windows 10 Professional license for 3 PCs meets this specific need. Reserve it for this scenario: if your machine can be upgraded to Windows 11, the upgrade is free, and that is the option to choose.

The case of environments with multiple devices

With five, ten, or thirty machines, the question is no longer technical but organizational. The method that works consists of three steps.

Take an inventory. One table, one row per device: model, processor, RAM, TPM, Windows 11 eligibility decision, and critical business software. Without this inventory, you will discover problems one by one, in no particular order, at the worst possible time.

Sort them into three groups. Devices eligible for migration (handle these first; upgrading them is free). Devices that are not eligible but are still performing well, making them candidates for ESU while you spread out the budget; first check which ESU applies to them: as soon as a device is joined to a domain, managed through MDM, or running in kiosk mode, the consumer offering is unavailable and paid commercial ESU applies. Finally, devices that need to be replaced anyway: group the replacements rather than paying for ESU for a machine you will discard in six months.

Don't forget what surrounds it. Windows 10's end of support is often an opportunity to discover that another part of your IT environment is in the same situation. On the server side, check the version in use and its own end-of-support date. Be careful not to confuse the two levels: Windows Server 2022 leaves mainstream support on October 13, 2026, but continues to receive security updates under extended support until October 14, 2031. In other words, no new features, but a security horizon that extends beyond that of many client devices.

For office software, the reasoning is the same: Office 2016 and Office 2019 reached end of support at the same time as Windows 10, and Office 2021 ends on October 13, 2026—that is, in just a few weeks at the time of writing. If you're going to migrate anyway, you might as well move to a version with a longer support horizon: Office 2024 Professional Plus for 3 PCs. And if you need to handle the operating system and office software at the same time, the Windows 11 Pro + Office 2024 Pro Plus bundle for 3 workstations avoids two separate orders.

What needs to be decided and when

Let's summarize, starting from your actual situation.

Your PC is eligible for Windows 11. Migrate without delay. It's free from an activated Windows 10 installation, and every month you wait is another month without security updates. Back up first.

Your PC is rejected because of its TPM. First, check the BIOS. A disabled option takes five minutes to enable; replacing hardware often costs several hundred euros. Check before drawing conclusions.

Your PC is rejected because of its processor. There is no proper software solution. You have two options: the ESU program to keep it running until its announced expiration date, or replacing the machine. Choose based on the workstation's age and what it actually runs.

You manage several workstations. Take inventory first, then migrate eligible workstations, and use ESU as a budget buffer for the rest, not as the destination. In the process, check which of the two ESU options applies to each machine.

The only bad choice is not making a choice. A workstation left on Windows 10 without ESU and without a decision is not in a stable situation: it is simply in a situation that is slowly deteriorating, until the day the problem is no longer theoretical. Take thirty minutes to assess the state of your IT environment, then decide for each workstation.

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