The “Activate Windows” watermark: why it appears and how to remove it
The text in the corner means Windows has no valid licence. The only lasting fix is activation.
Step 1: check the state
Open the Activation page and read the status and any error code.
Step 2: enter a key
Use Change product key. The watermark disappears soon after activation, sometimes after a restart.
If you replaced the motherboard
See activation after motherboard replacement.
What about “tricks” to hide it?
Registry edits and scripts only hide the text. Windows stays unactivated, and random scripts are a real security risk.
What changes after activation
Personalisation returns, reminders stop and the watermark goes.
Does the watermark slow down the PC?
No. It is a notice, not a performance limit.