How do I activate Windows 10 without a product key?

One of the first screens you’ll see will ask you to enter your product key so you can “Activate Windows.” However, you can just click the “I don’t have a product key” link at the bottom of the window and Windows will allow you to continue the installation process.

Why does my computer say Windows is not activated?

You might see this error if the product key has already been used on another device, or it’s being used on more devices than the Microsoft Software License Terms allow. … If you’re using Windows 10, you can buy Windows from the Microsoft Store: Select Start > Settings > Update & Security > Activation .