Re: How can I activate windows 10 free without product key?

If you don't have a product key and want to activate Windows 10 free, the most straightforward and legal way is to purchase and enter a valid Windows 10 product key.

​​Where to buy:​​

• Microsoft Store (https://www.microsoft.com)
• Authorized retailers (Amazon, Best Buy, etc.)
• OEM keys from computer manufacturers (if you're building or buying a PC)

Once you have the key:

1. Go to ​​Settings​​ > ​​Update & Security​​ > ​​Activation​​.

2. Click ​​Change product key​​.

3. Enter the 25-character product key and follow the prompts to activate Windows 10 for free.