Installing and activating Windows 11

There are two ways you end up on this page: either Windows 11 is already on the computer and you only need to enter the key, or you are starting from scratch. The first takes a minute, the second about half an hour — most of which runs without you.

If Windows 11 is already installed

  1. Open Settings → System → Activation.
  2. Choose Change product key.
  3. Enter the 25-character code from the e-mail and click Activate.

If the key field does not appear, Windows already counts as activated with another licence — check the status first, as described in the article on checking your licence.

Final check: press Windows + R, type slmgr /xpr and press Enter. It should say the machine is permanently activated.

If you are installing Windows 11 from scratch

Before you start

  • The computer must meet the requirements: TPM 2.0, Secure Boot and a reasonably recent processor. The check takes two minutes and is described here. If your computer does not qualify, Windows 10 Pro is the right choice.
  • A USB stick of at least 8 GB. Its contents are erased — move your files off it first.
  • A backup of anything important on the computer if you are doing a clean install.

Step 1 — download Microsoft's tool

Open the official Microsoft page for Windows 11 and choose Download tool now under “Create Windows 11 Installation Media”. This downloads the Media Creation Tool.

Do not download Windows from anywhere else. The installer is free and comes straight from Microsoft — you only pay for the licence.

Step 2 — make a bootable USB stick

  1. Run Media Creation Tool and accept the terms.
  2. Choose Create installation media (USB flash drive, DVD, or ISO file).
  3. Leave the language and edition at their defaults unless you need something else.
  4. Choose USB flash drive and select the stick.
  5. Wait — it downloads about 5 GB.

If Media Creation Tool will not run, download the ISO from the same page and build the stick with Rufus. The result is the same.

Step 3 — boot from the USB stick

  1. Leave the stick plugged in and restart the computer.
  2. Immediately after it starts, tap the boot-menu key — usually F12, F9, Esc or F2, depending on the make.
  3. Pick the USB stick from the list.

If the computer still loads the old Windows, go into BIOS/UEFI and put the USB stick first in the boot order.

Step 4 — install

Follow the steps on screen. When it asks for a product key you can enter it right away or choose I don't have a product key and activate after the install — the result is identical.

For a clean install choose Custom and select the partition. The computer will restart a few times; that is normal.

Step 5 — activate

Once the system is up, go back to the first part of this page: Settings → System → Activation → Change product key.

If something goes wrong

  • The key is rejected — usually the edition does not match. A Pro key will not activate Home, and the other way round. The remaining causes are collected in the article on activation errors.
  • Windows deactivates after a hardware change — normal behaviour; activation is tied to the motherboard. The fix is in the guide to transferring a licence.
  • Nothing helps — write to us at info@litsenzi.bg with your order number and a screenshot of the message. We help with activation free of charge, and if the key really does not work you get a replacement or a refund.

Don't have a licence yet?

Windows 11 Pro is for people who also use the computer for work — it adds BitLocker, Remote Desktop and domain join. Windows 11 Home covers home use. The differences are explained in the comparison of the two editions.

The key arrives by e-mail, usually within 15 minutes during business hours, together with an invoice.