Windows 7:How can i restrict access to WCN wizards

i have a computer at my home with Windows 7 operating system. I need your help regarding the Windows Connect Now wizards. My cousins sometimes try to add some wireless devices, they try to set access points in my pc. I stop them but they do this in my absences. So i need to restrict the access to WCn wizard. Could you guys help me out doing the same ? Please , its much needed

To do the same Go to Start menu, and type gpedit.msc in the search line and press Enter. If prompted by UAC, click on Continue. Go to User Configuration\Administrative Templates\Network\Windows Connect Now.

On the right side, double click on Prohibit Access to Windows Connect Now wizards.Now the windows open, select Enable and click ok. Thats it..

Now no one can access the Windows Connect Now wizards.

Its useful but i think locking computer is the best way of prevent the system from other users.