Activate Windows 10 , 8.1 , 8 & 7 by Phone
1. If you are performing a fresh installation of Windows 10, you will be prompted to enter your code during installation
2. After you complete the installation, follow the instructions in Step 3
3. If you want to enter/change your product key within Windows 10. Go to settings
4. Select Change Product key
5. Enter new Product key & click next
6.To activate Windows 10 by phone: Press the Win+R keys to open Run, then type: SLUI 4, then click on OK. (Note that there is a space between SLUI and 4.)
7. Select your country or region, then click Next.