Microsoft ended support for Windows 10 in October 2025. A computer with that system still boots, applications work, and the user notices nothing. And that is exactly the trap. The lack of a change visible on the screen makes the company put off the decision, while the risk grows quietly with every month.

What exactly is ending

The end of support does not mean the system suddenly switches off. It means Microsoft stops issuing free security patches. That is an important difference.

  • No patches for new vulnerabilities. Every gap discovered after this date stays open forever.
  • No technical support for the system as such.
  • Increasingly weak support in software. Over time, makers of browsers and applications stop testing and supporting the old platform.

There is a paid extended updates program, ESU, which prolongs the security patches alone for a certain time. It is a bridging solution, with it you buy months for a calm migration, not a permanent way of living with an old system.

Why this is a risk, not a formality

An unsupported operating system is the most convenient target for an attacker. The vulnerabilities are public and the patch will not come. A single such computer in the network is enough for it to become an entry point into the whole company.

In incident handling you regularly see the same pattern. The attack does not start from the most important server, but from the least well guarded machine. An old, unsupported computer is perfect for that.

On top of this comes a compliance layer that is easy to forget.

  • GDPR. Processing personal data on an unpatched system is hard to defend as an adequate security measure.
  • NIS2. Companies covered by the directive must demonstrate management of vulnerabilities and updates, and an unsupported system is the opposite of that.
  • Contracts and insurance. They increasingly require up-to-date software, and its absence can undermine a payout after an incident.
  • Certification. In an ISO/IEC 27001 environment an out-of-date system is a non-conformity that an auditor will catch immediately.

Check whether the hardware can handle Windows 11

The natural direction is a migration to Windows 11. It has, however, tougher hardware requirements than its predecessor, above all a TPM 2.0 module, Secure Boot mode and a compatible processor. Some company computers will go through the upgrade without a problem, some will not qualify.

That is why the first step is not buying hardware, but an inventory. You need to know how many workstations meet the requirements, how many only need TPM enabled in the settings, and how many are now fit only for replacement. Without this knowledge the migration budget is guesswork.

A step-by-step migration plan

  1. Inventory. Count all Windows 10 devices, check their compatibility with Windows 11 and note what runs where.
  2. Classification. Divide the hardware into three groups: ready to upgrade, requiring a settings change, for replacement.
  3. Applications. Check whether key company programs work on Windows 11. Most often the problem is old industry applications and drivers.
  4. Budget and schedule. Spread the replacements and upgrades over time, starting with the workstations at highest risk and with the greatest access to data.
  5. Pilot. Run the migration on a small group, catch the problems, and only then scale.
  6. Mass rollout. Automate installation and configuration, so you do not do each workstation by hand.
  7. Decommissioning the old. Securely wipe data from departing hardware before it leaves the company.

For companies with more workstations it is worth considering device management through Intune and accounts in Entra ID. Then such migrations, updates and policy rollouts are done centrally in the future, rather than by walking from desk to desk.

What not to do

  • Do not wait for an incident. A migration under pressure, after an attack or after an auditor’s refusal, costs many times more than a planned one.
  • Do not treat ESU as the goal. It is a time buffer, not a strategy.
  • Do not migrate everything at once. Stages and a pilot limit the risk of downtime.
  • Do not forget the servers. A similar end-of-support calendar applies to older Windows Server versions, worth checking on the occasion.

The end of Windows 10 support is not a failure, but a deadline that will not move on its own. Companies that treat it as a project will go through the migration calmly and tidy up their hardware along the way. If you want to start with a reliable assessment of the state, take a look at our IT audit, and we will lead the replacement itself and the further maintenance of the environment as part of managed IT services. The best moment for an inventory was yesterday, the second best is today.