| Microsoft DirectX 8.1 (C++) | 
Sets the service provider GUID in the address object. If a service provider is specified for this address, it is overwritten by this call.
HRESULT SetSP( const GUID *const pguidSP );
Returns S_OK if successful, or one of the following error values.
| DPNERR_INVALIDPOINTER | 
| DPNERR_NOTALLOWED | 
  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.