WMI in C# .NET Giving Different Results to WMI in Native C DLL

[FunkyStuff]

Hey,

I'm using WMI in C# .NET to retrieve some hardware information, including the current Win32_VideoController "Name". In C# on Windows 8 for a lot (or possibly all) people it seems to obtain information about a completely different video controller to that of when my native C DLL requests the same information.

For example, in Windows 8 the name seems to say "Microsoft Basic Render Driver" with C# and "NVIDIA GeForce 550 TI" via my native DLL. Why would this happen?

Here's my C# code:

ManagementObject managementObject1;
object object1;
string string1 = "";
foreach (QueryPair queryPair1 in new QueryPair[] { new QueryPair("Win32_Processor", "Name"), new QueryPair("Win32_VideoController", "Name") })
{
    try
    {
        using (ManagementObjectSearcher managementObjectSearcher1 = new ManagementObjectSearcher (("SELECT * FROM " + queryPair1.Query)))
        {
            using (ManagementObjectCollection managementObjectCollection1 = managementObjectSearcher1.Get ())
            {
                using (ManagementObjectCollection.ManagementObjectEnumerator managementObjectEnumerator1 = managementObjectCollection1.GetEnumerator ())
                {
                    if (managementObjectEnumerator1.MoveNext ())
                    {
                        managementObject1 = ((ManagementObject) managementObjectEnumerator1.Current);
                        object1 = managementObject1[queryPair1.Member];
                        string1 = (string1 + "|" + ((object1 != null) ? object1.ToString ().Replace("|", "-") : "?"));
                    }
                }
            }
        }
    }
    catch
    {
    }
} 

And here's my native C code:

    // Step 3: ---------------------------------------------------
    // Obtain the initial locator to WMI -------------------------

    IWbemLocator *pLoc = NULL;

    hres = CoCreateInstance(
        CLSID_WbemLocator,             
        0, 
        CLSCTX_INPROC_SERVER, 
        IID_IWbemLocator, (LPVOID *) &pLoc);
 
    if (FAILED(hres))
    {
        //CoUninitialize();
        return 1;                 // Program has failed.
    }

    // Step 4: -----------------------------------------------------
    // Connect to WMI through the IWbemLocator::ConnectServer method

    IWbemServices *pSvc = NULL;
    
    // Connect to the root\cimv2 namespace with
    // the current user and obtain pointer pSvc
    // to make IWbemServices calls.
    hres = pLoc->ConnectServer(
         _bstr_t(L"ROOT\\CIMV2"), // Object path of WMI namespace
         NULL,                    // User name. NULL = current user
         NULL,                    // User password. NULL = current
         0,                       // Locale. NULL indicates current
         wbemConnectFlagUseMaxWait,                    // Security flags.
         0,                       // Authority (for example, Kerberos)
         0,                       // Context object 
         &pSvc                    // pointer to IWbemServices proxy
         );
    
    if (FAILED(hres))
    {
        pLoc->Release();     
        //CoUninitialize();
        return 1;                // Program has failed.
    }

    // Step 5: --------------------------------------------------
    // Set security levels on the proxy -------------------------

    hres = CoSetProxyBlanket(
       pSvc,                        // Indicates the proxy to set
       RPC_C_AUTHN_WINNT,           // RPC_C_AUTHN_xxx
       RPC_C_AUTHZ_NONE,            // RPC_C_AUTHZ_xxx
       NULL,                        // Server principal name 
       RPC_C_AUTHN_LEVEL_CALL,      // RPC_C_AUTHN_LEVEL_xxx 
       RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx
       NULL,                        // client identity
       EOAC_NONE                    // proxy capabilities 
    );

    if (FAILED(hres))
    {
        pSvc->Release();
        pLoc->Release();     
        //CoUninitialize();
        return 1;               // Program has failed.
    }

    GetWMIRequest(pSvc, L"Win32_VideoController", L"Name"); 

BSTR GetWMIRequest(IWbemServices *pSvc, BSTR service, BSTR prop)
{
    HRESULT hres;

    // Step 6: --------------------------------------------------
    // Use the IWbemServices pointer to make requests of WMI ----

    // For example, get the name of the operating system
    IEnumWbemClassObject* pEnumerator = NULL;
    hres = pSvc->ExecQuery(
        bstr_t("WQL"), 
        bstr_t("SELECT * FROM ") + service,
        WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY, 
        NULL,
        &pEnumerator);

    // Step 7: -------------------------------------------------
    // Get the data from the query in step 6 -------------------
 
    IWbemClassObject *pclsObj;
    ULONG uReturn = 0;

    VARIANT vtProp;
   
    while (pEnumerator)
    {
        HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1, 
            &pclsObj, &uReturn);

        if(0 == uReturn)
        {
            break;
        }

        // Get the value of the Name property
        hr = pclsObj->Get(prop, 0, &vtProp, 0, 0);
        VariantClear(&vtProp);
    }

    pEnumerator->Release();
    pclsObj->Release();

    return vtProp.bstrVal;
} 

I know in the native code I'm explicitly connecting to the "ROOT\CIMV2" scope, but I did try doing that in C# and it made no difference.

Why would these 2 bits of code get information about 2 completely different video controllers on the same computer? And they even run in the same process. The C# code runs inside a C# .NET exe, and the native DLL is loaded by the C# .NET exe and called via an export in the DLL.

Help appreciated!