Some users still believe that the Windows 10 operating system is free. But that is simply wrong. A valid product key or license is required for operation. Many users have the early offer in the course of the switch to Windows 10
Claimed and upgraded their older Windows version such as Windows 7.
In this case, they received the Windows 10 license for 1 year free of charge. If you also reinstall Windows 10 on your computer without a license key, you can use the operating system for 1 month without a product key. In this case, the purchase of such a product key is necessary. However, if you have a valid license, the hint may be a general problem. In the following solutions, we will show you in individual steps how you can tackle and eliminate the problem.