Hi, here it is my code through which I am successfully initialize the VDS service and get the Packs but When I call QueryVolumes on IVdsPack Object, I am able to get IEnumVdsObjects but unable to get IUnknown* array through IEnumVdsObject::Next method, it reutrns S_FALSE with IUnkown* = NULL. So this IUnknown* cant be used to QueryInterface for IVdsVolume

Below is my code

    HRESULT hResult;
IVdsService* pService = NULL;
IVdsServiceLoader *pLoader = NULL;

//Launch the VDS Service
hResult = CoInitialize(NULL);
if( SUCCEEDED(hResult) )
{
    hResult = CoCreateInstance( 
                                CLSID_VdsLoader,
                                NULL,
                                CLSCTX_LOCAL_SERVER,
                                IID_IVdsServiceLoader,
                                (void**) &pLoader
                                );

    //if succeeded load VDS on local machine
    if( SUCCEEDED(hResult) )
        pLoader->LoadService(NULL, &pService);

    //Done with Loader now release VDS Loader interface
    _SafeRelease(pLoader);

    if( SUCCEEDED(hResult) )
    {
        hResult = pService->WaitForServiceReady();
        if ( SUCCEEDED(hResult) )
        {
            AfxMessageBox(L"VDS Service Loaded");
            IEnumVdsObject* pEnumVdsObject = NULL;
            hResult = pService->QueryProviders(VDS_QUERY_SOFTWARE_PROVIDERS, &pEnumVdsObject);

            IUnknown* ppObjUnk ;
            IVdsSwProvider* pVdsSwProvider = NULL;
            IVdsPack* pVdsPack = NULL;
            IVdsVolume* pVdsVolume = NULL;
            ULONG ulFetched = 0;

            hResult = E_INVALIDARG;
            while(!SUCCEEDED(hResult))
            {
                hResult = pEnumVdsObject->Next(1, &ppObjUnk, &ulFetched);
                hResult = ppObjUnk->QueryInterface(IID_IVdsSwProvider, (void**)&pVdsSwProvider);
                if(!SUCCEEDED(hResult))
                    _SafeRelease(ppObjUnk);
            }
            _SafeRelease(pEnumVdsObject);
            _SafeRelease(ppObjUnk);

            hResult = pVdsSwProvider->QueryPacks(&pEnumVdsObject);

            hResult = E_INVALIDARG;
            while(!SUCCEEDED(hResult))
            {
                hResult = pEnumVdsObject->Next(1, &ppObjUnk, &ulFetched);
                hResult = ppObjUnk->QueryInterface(IID_IVdsPack, (void**)&pVdsPack);
                if(!SUCCEEDED(hResult))
                    _SafeRelease(ppObjUnk);
            }

            _SafeRelease(pEnumVdsObject);
            _SafeRelease(ppObjUnk);

            hResult = pVdsPack->QueryVolumes(&pEnumVdsObject);
            pEnumVdsObject->Reset();

            hResult = E_INVALIDARG;
            ulFetched = 0;
            BOOL bDone = FALSE;
            while(!SUCCEEDED(hResult))
            {
                hResult = pEnumVdsObject->Next(1, &ppObjUnk, &ulFetched);
                //hResult = ppObjUnk->QueryInterface(IID_IVdsVolume, (void**)&pVdsVolume);
                if(!SUCCEEDED(hResult))
                    _SafeRelease(ppObjUnk);
            }
            _SafeRelease(pEnumVdsObject);
            _SafeRelease(ppObjUnk);
            _SafeRelease(pVdsPack);
            _SafeRelease(pVdsSwProvider);

// hResult = pVdsVolume->AddAccessPath(TEXT("G:\"));

            if(SUCCEEDED(hResult))
                AfxMessageBox(L"Add Access Path Successfully");
            else
                AfxMessageBox(L"Unable to Add access path");

            //UUID of IVdsVolumeMF {EE2D5DED-6236-4169-931D-B9778CE03DC6}
            static const GUID GUID_IVdsVolumeMF = {0xEE2D5DED, 0x6236, 4169,{0x93, 0x1D, 0xB9, 0x77, 0x8C, 0xE0, 0x3D, 0XC6} };

            hResult = pService->GetObject(GUID_IVdsVolumeMF, VDS_OT_VOLUME, &ppObjUnk);
            if(hResult == VDS_E_OBJECT_NOT_FOUND)
                AfxMessageBox(L"Object Not found");
            if(hResult == VDS_E_INITIALIZED_FAILED)
                AfxMessageBox(L"Initialization failed");

// pVdsVolume = reinterpret_cast(ppObjUnk);

            if(SUCCEEDED(hResult))
            {

// hResult = pVdsVolume->AddAccessPath(TEXT("G:\")); if(SUCCEEDED(hResult)) { IVdsAsync* ppVdsSync; AfxMessageBox(L"Formatting is about to Start......"); // hResult = pVdsVolume->Format(VDS_FST_UDF, TEXT("UDF_FORMAT_TEST"), 2048, TRUE, FALSE, FALSE, &ppVdsSync); if(SUCCEEDED(hResult)) AfxMessageBox(L"Formatting Started......."); else AfxMessageBox(L"Formatting Failed"); } else AfxMessageBox(L"Unable to Add Access Path"); } _SafeRelease(pVdsVolume); }

        else
        {
            AfxMessageBox(L"VDS Service Cannot be Loaded");
        }
    }
}
_SafeRelease(pService);