The kernel component is a low level operating system component which sits between your network adapter and the operating system. It is there that the actual bandwidth control occurs. If you have two or more network adapters in your system, then a seperate instance of the kernel component is loaded for each one.
The kernel component is classified as a network driver and therefore runs at a higher 'privilege' than most other programs. Drivers have direct access to all hardware in a machine, whereas normal programs must request access to hardware, memory and other low level system resources.
But because the operating system gives drivers such freedom, they do not receive any protection from themselves. That is, if there is a bug or unpredicted behaviour in a driver, the operating system has no choice but to halt the system. This manifests as a System Bug Check, better known as a 'Blue Screen'.
Bandwidth Controller has been exhaustively tested, but it is still possible that such a problem may occur on a system with certain network adapters and drivers.
The kernel component starts at bootup and ends when the system shuts down. It does not require a user be logged into the machine to work.
To configure the kernel component, you must log in and run the manager.