You may see this error because the Windows 10 product key you entered isn’t valid. Product keys are unique—assigned to a specific user to install on a single device. If a key was used (or attempted to be used) on multiple devices, it’s marked as not valid. To activate Windows, you’ll need to provide a different Windows key unique to your device.
If you bought a device from a reseller of Windows 10 and expected the key to be valid, contact the reseller. If your device was purchased with Windows 10 preinstalled and you received this activation error upon turning it on for the first time, contact your device manufacturer.
If your experience with your device is different from those listed above, try the following:
- Run the Windows 10 Activation Troubleshooter: Select Start > Settings > Update & Security > Activation and then select Troubleshoot .
Open Activation settings
- Check to see if you have a paper copy of your Windows 25-character product key you can enter to activate Windows 10.
- If your device was recently repaired at an independent repair facility, contact them to see if the repairs require a new Windows 10 license.
- If the device is new and has never been activated, contact your device manufacturer.