The HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services subkey is the service registration area that contains the information used to load a network component into memory. These subkeys contain certain required information, such as the location of the executable file, the service type, and its start criterion.
Each network component's software registration information (as described in the previous section) contains an entry named ServiceName, whose value is the name of the service corresponding to the network component. This name acts as a symbolic link to the CurrentControlSet\Services parameters.
Some network components are actually sets of services, each of which has its own subkey in the Services subkey. There is usually a "main" service, with the other services listed as its dependencies.
For example, as shown in the previous section, the Etherlink driver's ServiceName is Elnkii, and this name would appear as a Services subkey that defines the location of the driver file, dependencies, and other startup information. The Elnkii subkey in turn contains other subkeys that define the parameters and linkage rules for the driver.
The Etherlink adapter's ServiceName is Elnkii02, which also appears as a Services subkey that defines linkage rules for bindings plus physical parameters of the network card, such as its I/O address and interrupt request (IRQ) number, as specified in the Network dialog in Control Panel.
The value entries for the subkeys describing adapters and drivers are defined in "Registry Entries for Network Adapter Cards" in Chapter 14, "Registry Value Entries."