To activate Microsoft Windows 10 code, follow the guide below:
If you are performing a fresh installation of Windows 10, you will be prompted to enter your code during installation
After you complete the installation, follow the instuctions in Step 3
If you want to enter/change your product key within Windows 10, follow the screenshot below:
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.)
Select your country or region, then click Next.
Call the provided phone number to reach the Microsoft Product Activation Center. You will first be walked through an automated menu where you must answer a few questions about what product you are trying to activate (Windows 10), whether you have previously activated it (No), and whether you have a product key (Yes).
The automated system will now describe the Internet Activation process to you. You already know this information, but simply wait for it to complete. At the end, the system will ask you if you still need assistance. Tell it “Yes”, and then you will be taken to a human operator.
The human operator will ask confirmation of what product you are trying to activate (Windows 10), and then they will ask you if you have an Installation ID (Yes – it’s on the same screen as the phone number you called).
The human operator will then ask you to read them that number. I’ve found you can read it to them relatively quickly and they keep up just fine; and if you speak clearly, you usually only have to read it once.
The human operator will then turn you back over to the automated telephone system, which after a few brief instructions will read your Confirmation ID to you. So once the human operator hands the call back to the automated system, click “Enter Confirmation ID” and type in the numbers when they are read to you.
Once you have entered the Confirmation ID, you can click Activate Windows and if your product key is valid and the numbers have been typed in correctly, you should be all set.