Just Set the followin before 'NvFBCCreateParams params;'
int magic[] = { 0x0D7BC620, 0x4C17E142, 0x5E6B5997, 0x4B5A855B };

And after set/replace this :
NvFBCCreateParams params;
ZeroMemory(&params, sizeof(NvFBCCreateParams));
params.dwVersion       = NVFBC_CREATE_PARAMS_VER;
params.dwInterfaceType = NVFBC_TO_SYS;
params.pDevice         = NULL;
params.dwAdapterIdx    = 0;
params.pPrivateData      = &magic;
params.dwPrivateDataSize = sizeof(magic);

if (m_fnCreateEx(&params) != NVFBC_SUCCESS)
{

@Soft Camel : I love you for this !