[This is preliminary documentation and subject to change.]
Requirement (Designed for Microsoft® Windows® Logo)
Communications applications that dial, answer, and otherwise control telephone calls on equipment such as modems, ISDN adapters, and telephones must control those calls using the Windows Telephony Application Programming Interface (TAPI).
This includes online registration of an application. All telephony-enabled applications must either use the full TAPI interface or must pass requests to a telephony-centric application that does.
For more information about writing TAPI service providers, see the TAPI Service Provider documentation.