If you select System level, Kill Switch will function even if the VyprVPN app is not running. However, if you log out of the VyprVPN app, Kill Switch will not function, regardless of whether the VyprVPN app is running or not.
This is made possible by the VyprVPN Windows service, which runs even when the VyprVPN app is closed. If the service is terminated, or if you log out of the VyprVPN app, then Kill Switch will cease to function entirely.
(Note: If you enable Kill Switch on the System level, you will have no Internet connectivity even when you have exited the VyprVPN app. To re-establish your Internet connection, you must start VyprVPN and either connect to VyprVPN, or disable Kill Switch from the app settings.)
If you need any further assistance, please contact our 24/7 Customer Success Team, who would be glad to assist.