HRESULT GetWbemService(IWbemServices **pWbemService)
{
    IWbemServices *pWbemServ = NULL;
    IWbemLocator *pLoc = 0;
    HRESULT hr;

    hr = CoCreateInstance(CLSID_WbemLocator, 0,
        CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLoc);

    if (FAILED(hr))
    {
        cout << "Failed to create IWbemLocator object. Err code = 0x"
             << hex << hr << endl;
        CoUninitialize();
        return hr;     // Program has failed.
    }

    // Connect to the root\default namespace with the current user.
    hr = pLoc->ConnectServer(
            BSTR(L"ROOT\\cimv2"),
            NULL, NULL, 0, NULL, 0, 0, pWbemService);

    if (FAILED(hr))
    {
        cout << "Could not connect. Error code = 0x"
             << hex << hr << endl;
        pLoc->Release();
        CoUninitialize();
        return hr;      // Program has failed.
    }

    return S_OK;    
}

void InitCOM()
{
    CoInitializeEx(0, COINIT_MULTITHREADED);

    CoInitializeSecurity(
        NULL,
        -1,                          // COM authentication
        NULL,                        // Authentication services
        NULL,                        // Reserved
        RPC_C_AUTHN_LEVEL_DEFAULT,   // Default authentication
        RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation  
        NULL,                        // Authentication info
        EOAC_NONE,                   // Additional capabilities
        NULL                         // Reserved
        );


}
void WMIQuery()
{


    BSTR language = SysAllocString(L"WQL");
    BSTR query = SysAllocString(L"Select * FROM Win32_DiskDrive");
    // Other query otptions may be 1) Win32_LogicalDisk 2) Win32_DiskDrivePhysicalMedia

    // Create querying object
    IWbemClassObject *pObj = NULL;
    IWbemServices *pServ = NULL;
    IEnumWbemClassObject *pEnum = NULL;
    HRESULT hRet;

    if(FAILED(GetWbemService(&pServ))) { return; }

    // Issue the query.
    hRet = pServ->ExecQuery(
        language,
        query,
        WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,         // Flags
        0,                              // Context
        &pEnum
        );


    SysFreeString(language);
    SysFreeString(query);
        
    if(FAILED(hRet)) { return; }
    // Get the disk drive information
    ULONG uTotal = 0;

    // Retrieve the objects in the result set.
    for (;;)
    {
        ULONG uReturned = 0;

        hRet = pEnum->Next(
            0,                  // Time out
            1,                  // One object
            &pObj,
            &uReturned
            );

        uTotal += uReturned;

        if (uReturned == 0)
            break;
        VARIANT val;

        pObj->Get(L"Name", 0, &val, NULL, NULL);
        wcout << "name: " << val.bstrVal << endl;

        pObj->Release();    // Release objects not owned.            
    }

    // All done.
    pEnum->Release();
    pServ->Release();

        
}

int main()
{
    // Initialize COM
    InitCOM();

    WMIQuery();

    CoUninitialize();
}