Cant get "Description" from Win32_OperatingSystem class - c++

Question

I try to get Description from Win32_OperatingSystem, the main problem that i takes empty string.
I dont understand why, when i try to take something else from Win32_OperatingSystem, with type string, i can get it.
Can there be situation when Description is empty? Or its just bug in my code...?
Code:
STDMETHODIMP CSystemInfo::GetOS(CString* SystemInfo )
{
HRESULT hres;
CString tmp;
hres = GetInfo( TEXT( "Win32_OperatingSystem" ), TEXT( "Description" ), &tmp );
if( FAILED( hres ) )
{
return E_FAIL;
}
SystemInfo->SetString( tmp.GetString() );
return S_OK;
}
STDMETHODIMP CSystemInfo::GetInfo( CString className, CString propertyName, CString* info )
{
HRESULT hres;
IWbemLocator* pLoc = NULL;
IWbemServices* pSvc = NULL;
IEnumWbemClassObject* pEnumerator = NULL;
bool initialized = true;
hres = CoInitialize( NULL );
if( FAILED( hres ) )
{
return E_FAIL;
}
hres = 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
);
if( FAILED( hres ) && hres != RPC_E_TOO_LATE )
{
}
hres = CoCreateInstance(
CLSID_WbemLocator,
0,
CLSCTX_INPROC_SERVER,
IID_IWbemLocator, ( LPVOID* )&pLoc );
if( FAILED( hres ) )
{
return E_FAIL;
}
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
NULL, // Security flags.
0, // Authority (for example, Kerberos)
0, // Context object
&pSvc // pointer to IWbemServices proxy
);
if( FAILED( hres ) )
{
return E_FAIL;
}
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 ) )
{
return E_FAIL;
}
CString tmp = TEXT( "SELECT * FROM ");
tmp += className.GetString();
hres = pSvc->ExecQuery(
bstr_t( "WQL" ),
bstr_t(tmp.GetString()),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator );
if( FAILED( hres ) )
{
return E_FAIL;
}
IWbemClassObject* pclsObj = NULL;
ULONG uReturn = 0;
while( pEnumerator )
{
HRESULT hr = pEnumerator->Next( WBEM_INFINITE, 1, &pclsObj, &uReturn );
if( uReturn == 0 )
{
break;
}
VARIANT vtProp;
hr = pclsObj->Get(propertyName.GetString(), 0, &vtProp, 0, 0 );
if( FAILED( hres ) )
{
return E_FAIL;
}
info->SetString( vtProp.bstrVal );
VariantClear( &vtProp );
pclsObj->Release();
}
CoUninitialize();
return S_OK;
}
Thats how i calling my function
HRESULT hr;
CoInitialize( NULL );
CSystemInfo* cSystem = NULL;
CLSID clsid;
hr = CLSIDFromProgID( L"Server.Inproc.1" , &clsid );
if( FAILED( hr ) )
{
std::cout << "Cant get CLSID " << std::endl;
}
hr = CoCreateInstance( clsid,NULL, CLSCTX_INPROC_SERVER, IID_ISystemInfo, ( void** )&cSystem );
if( FAILED( hr ) )
{
std::cout << "Cant Create Instance" << std::endl;
}
CString tmp;
hr = cSystem->GetOS( &tmp );
std::wcout << "OS Info: \t" ;
std::wcout << tmp.GetString() << std::endl;
Also i cant get description from Win32_DesktopMonitor.

Answer 1

You can check whether "Description" property is present or not by executing gwmi Win32_OperatingSystem command on Windows PowerShell. I cannot find the "Description" property of Win32_OperatingSystem on my pc.