EasyAbout 10 minutesWindows

An Activate Windows watermark sits on your screen

Why does my computer say Activate Windows in the corner?

CF

Written by The CommonFixes team · fact checked by CommonFixes review desk

Last updated

Short answer

Windows ties its licence to your hardware. Replacing a motherboard or drive, or a failed check after an update, makes Windows think it is on a new machine. The quickest thing to try first: run the activation troubleshooter — Settings, System, Activation, then Troubleshoot. If you changed hardware, choose I changed hardware on this device recently and sign in with the Microsoft account that owned the licence. Most people are done in about 10 minutes.

Full walkthrough below: 4 steps for Windows, rated easy.

Sounds like this

  • Faint text over the bottom right corner
  • Personalisation settings greyed out
  • Appeared after a repair or new part

Why it happens

Windows ties its licence to your hardware. Replacing a motherboard or drive, or a failed check after an update, makes Windows think it is on a new machine.

Work through these in order

0% done
  1. 1

    Run the activation troubleshooter

    Settings, System, Activation, then Troubleshoot. If you changed hardware, choose I changed hardware on this device recently and sign in with the Microsoft account that owned the licence.

  2. 2

    Link the licence to your account

    Once activated, keep signing in with that same Microsoft account under Settings, Accounts, Your info. The licence then follows you through future repairs.

  3. 3

    Enter the product key

    Settings, System, Activation, Change product key. Retail keys arrive by email or on a card, and many laptops store the key in firmware and reactivate on their own once online.

  4. 4

    Check the internet and clock

    Activation needs a working connection and a correct date. Fix both, then press Activate again.

If none of that worked

If the computer was bought second hand with no licence, buy a key from Microsoft or a reputable retailer. Cheap grey market keys are usually stolen volume licences and stop working within weeks.

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Who wrote this and how we checked it

CF

The CommonFixes team

Writer and researcher

We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.

  • Everyday repairs
  • Windows and Mac
  • Plain language
RD

CommonFixes review desk

Technical editor

Before a guide goes live, a second person walks through it on a real machine and checks each instruction against the maker's own support pages. Anything we cannot confirm is removed rather than guessed at.

  • Fact checking
  • Safety warnings
  • Source links

This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.

A gentle reminder: back up anything you cannot afford to lose before major repairs. If a step ever feels risky, stop and ask a technician. There is no shame in that.