Preliminary test versions of Windows 10 already contain the key included in the distribution and are automatically activated when connected to the Internet.
Activation of Windows 10 on most computers occurs automatically when you connect your computer or laptop to the Internet, if the system was not activated automatically in your case, Microsoft has released several official and obviously free Windows 10 product keys
The keys are categorized according to the version of Windows 10
Windows 10 activation keys
Windows 10 Professional activation keys
Windows 10 Home Single Language
Windows 10 Enterprise activation keys
If for some reason you did not find any key that works for you, you can download Windows 10 activator - a small program, designed for the activation of Win 10.