| Microsoft DirectX 8.1 (C++) | 
Retrieves the service provider GUID in the address object. If no service provider is specified, this method returns DPNERR_DOESNOTEXIST.
HRESULT GetSP( GUID* pguidSP );
Returns S_OK if successful, or one of the following error values.
| DPNERR_DOESNOTEXIST | 
| DPNERR_INVALIDPOINTER | 
  Windows NT/2000/XP: Available as a redistributable for Windows 2000 and later.
  Windows 98/Me: Available as a redistributable for Windows 98 and later.
  Header: Declared in Dpaddr.h.