| Microsoft DirectX 8.1 (C++) | 
Frees the specified private data associated with this volume.
HRESULT FreePrivateData( REFGUID refguid );
If the method succeeds, the return value is D3D_OK.
If the method fails, the return value can be one of the following values.
| D3DERR_INVALIDCALL | 
| D3DERR_NOTFOUND | 
Microsoft® Direct3D® calls this method automatically when a volume is released.
  Header: Declared in D3d8.h.
  Import Library: Use D3d8.lib.
IDirect3DVolume8::GetPrivateData, IDirect3DVolume8::SetPrivateData