Sometimes Windows has problem with activation. We can easy solve this problem from command line.
Activation Windows from Command Line:
Find CMD and “Run as administrator”
Type: slmgr -ipk your-mak-key-here
If everything went well you will see this windows
Type: slmgr -ato
Deactivation Windows from Command Line:
Find CMD and “Run as administrator”.
Type: slmgr -upk
If everything went well you will see this window.
Now your Windows installation is fully genuine.