HKLM\SYSTEM\CurrentControlSet\Services\RasMan\PPP\ControlProtocols\
The BuiltIn subkey stores configuration data for PPP control protocols and authentication protocols that are included in Windows 2000.
Note
For Windows 2000, the PPP subkey has a ControlProtocols subkey. Entries for control protocols, such as CBCP, IPCP, and IPXCP, that were located in the PPP subkeys for Windows NT 4.0 and earlier now appear in the RasMan\PPP\ControlProtocols\BuiltIn subkey.