This copy of windows is not genuine solution

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.

5. Now you will see a confirmation window, click on OK.
6. Restart your PC.
Now you will never receive error message. If you see same error message, then try SLMGR /REARM instead SLMGR -REARM.
Command SLMGR -REARM works for Windows 32 bit version. It even work for windows 64 bit version. Some times this command will not work for Windows 64 bit version. Then only try SLMGR /REARM instead SLMGR -REARM.
After following above procedure, you may remove windows not genuine error. But there is chance that you may have black background. In that case, change the background by going in to system properties. You can also re install OS and follow procedure.
 If you get “Error 0xc004d307 : The maximum allowed number of rearms has been exceeded” after entering command. Read my article about How to fix Error 0xc004d307 to re-arm again. 

 If you get error “slmgr is not recogized as an internal or external command” after entering command. Read my article about How to fix slmgr is not recognized as an internal or external command.
Enjoy the windows 7 like original windows 7. But it is not enough, you must follow below steps to get error free Windows for lifetime.
          As you are not using original windows, you are not authorised to update windows. If you update windows, Microsoft will install one file which can detect your window is genuine or not. So follow the below steps to switch off windows automatic update.
1. open control panel.
2. Go to windows update.
3. Click on “Install updates automatically(Recommended)”.
4. Select “never check for updates(Not recommended)”