Back up the registry before apply in changes
disable store via the registry perform the following:
Start the registry editor (regedit.exe)
Navigate to HKEYCURRENTUSER\SOFTWARE\Policies\Microsoft\WindowsStore (if the WindowsStore key is not present then create it)
Create a new DWORD value named RemoveWindowsStore and set to value 1
Log out and then log in for the change to take affect
Via Group Policy navigate to User Configuration\Policies\Administrator Templates\Windows Components\Store and set the Turn off the Store application policy to enabled.
If you try and launch the Store a notification that the application is blocked appears and it will close.