1. Click on start menu.

2.Type cmd in search field.

3.Right click on cmd file and click on Run as Administrator.It is must to run command prompt with administrator privileges.

4. Type SLMGR -REARM (SLMGR is Windows software licensing management tool. REARM command will reset the licensing status of machine) and press enter.

This copy of windows is not genuine

5. Now you will see a confirmation window, click on OK.

6. Restart your PC.