How to activate Windows 11 Pro and make the licence survive a reinstall

Get four things into the same place before you open anything: the PC itself, an administrator account on it, a connection that works, and either the 25-character product key or the Microsoft account that already holds the digital licence.

• Windows 11 already installed. Activation does not install anything — it licenses the copy that is already on the machine.
• Your current edition. Press Windows and R, type winver, press Enter. The first line tells you whether you are on Home or Pro.
• An administrator account. A standard user account cannot change the product key.
• Internet at the moment you activate. Phone activation still exists, but it is slower and more fragile.
• A Microsoft account, ideally. Optional for activation itself, close to essential afterwards, for the reason explained further down.

One thing to know about us: ROSH™ Company Labs is a one-person business in Morocco with no link to Microsoft — not a partner, not an authorised reseller, not an agent, affiliated with nobody. We sell genuine licences at Moroccan prices and close orders on WhatsApp. We are not a registered company and we issue no tax invoice, so if your accountant needs one, buy elsewhere. Windows 11 Pro is quoted case by case: contact for pricing. Buying is at your own risk.

Do them in this order. On a decent connection it takes about five minutes, plus a restart if you are moving from Home to Pro.

1. Connect the PC to the internet and sign in with an administrator account.
2. Press Windows and I to open Settings, then go to System › Activation.
3. Read what is already there. If Activation state says Active, you are finished. If not, carry on.
4. On Windows 11 Home with a Pro key: open Upgrade your edition of Windows, then Change product key › Change.
5. On Windows 11 Pro that is not activated: open the Activation state row instead, then Change product key › Change.
6. Type the key. Dashes are added for you and lower case is fine. The digit 0 and the letter O are what people get wrong.
7. Select Next and let it finish. The screen may go dark briefly. A Home to Pro upgrade restarts the PC and keeps your files, apps and settings.
8. Link the account: Settings › Accounts › Your info, then Sign in with a Microsoft account instead.
9. Go back to System › Activation and read the wording one last time.

Step eight is the one almost everyone skips and later regrets. It is what turns a key you can lose into a licence Microsoft recognises on its own.

The exact sentence you want: under Settings › System › Activation, the Activation state reads Active, and underneath it Windows says it is activated with a digital licence linked to your Microsoft account. If the words about the account are missing, activation worked but the licence is not tied to you yet — go back and sign in.

• Edition check: run winver again. It should now say Windows 11 Pro.
• Licence check: open Windows Terminal or Command Prompt and run slmgr /xpr. A perpetual Windows licence answers that the machine is permanently activated.
• Microsoft’s own side: sign in at account.microsoft.com with the linked account and open Devices. Your PC appears there by name.

Here is the inconvenient part. Microsoft publishes no page that shows a Windows licence certificate for your PC. The Activation page inside Settings is the authoritative view; the device list on the Microsoft site only proves the machine is attached to your account. Third-party key checkers prove nothing at all and often exist to collect keys, so do not paste yours into one. Take a screenshot of the Activation page while it reads Active — it costs nothing and it is useful the day something changes.

Most failures are one of these. None need Windows reinstalled.

• 0xC004F050 — the key was refused as invalid. Usually the wrong edition, a Home key typed into Pro, or a plain typo.
• 0x803FA067 — the key does not fit this upgrade path, usually because it belongs to a different edition.
• 0xC004C003 — Microsoft’s server refused the key because it is blocked or already in use on another machine. Nothing local fixes this. Go back to whoever sold it to you.
• Windows cannot activate right now, try again later — often a temporary server problem. Wait an hour, then run Settings › System › Activation › Troubleshoot.
• Activation lost after a motherboard or drive swap — run the same Troubleshoot option, choose the line about recently changed hardware, then sign in and pick the PC from the list.
• No internet at all — press Windows and R and run slui 4 to reach the telephone activation wizard.

If a key we sold you fails, send us the error and its code on WhatsApp and we will do what we can. We promise no refund, warranty or guarantee: we are not the vendor and cannot overrule Microsoft’s activation servers. Meanwhile an unactivated Windows keeps working — personalisation is greyed out and a watermark sits in the corner, but security updates keep arriving.

There is no renewal date. A Windows 11 Pro licence is perpetual. It does not run for three months or a year like a Microsoft 365 subscription, and nothing expires on a calendar. What can change is the machine the licence lives on.

• Reinstalling Windows: choose the option saying you have no product key during setup, finish the install, connect to the internet, and the digital licence reactivates by itself within a few minutes.
• Changing parts: memory, drives and graphics cards rarely matter. A motherboard swap usually does, and that is precisely the case the account link and the troubleshooter exist for.
• Moving to a new PC: whether the licence can move depends on its type. An OEM licence stays with the machine it first activated on; a retail licence can be transferred. Tell us before you buy if that matters.
• Updates: version upgrades within Windows 11 stay free on an activated PC. For context, Windows 10 left standard support on 14 October 2025.

Keep two things somewhere safe: the key, and access to the Microsoft account you linked. Losing the account is worse than losing the key. And keep your expectations calibrated — one person, no affiliation with any vendor, no invoice, no legal guarantee behind the sale. That is the honest trade for the price.