The Windows 10 product key is a label that is usually stuck on the back of the computer or on the bottom of the notebook you purchased.
If you have purchased a license on CD, the code is always inserted into the package in the form of a label.
If you have upgraded and do not have a label, you can easily find it on your Microsoft Account.
In any case this is the procedure to find the product key:
- Right click on the START button with the right mouse button
- Click on System