IWbemLocator::ConnectServer (WMI) crashes in Windows 7 - c++

Question

I am writing a simple x86 application for extracting Harddrive/storage info by using WMI. The development environment is MS Visual Studio 2013 Update 5. However, everytime my code reaches this part :
hr = (*pLoc)->ConnectServer(....);
I receive this error
"Unhandled exception at 0x6C2BD183 (wbemcomn.dll) in HDDExtractor.exe: 0xC0000005: Access violation writing location 0x00DB9CAA"
The funny thing is that, this error occurs on the PCs with Windows 7, however it always works perfectly fine on PCs with Windows 10.
Below is the excerpt of the source code :
#include <iostream>
#include <winsock2.h>
#include <Winbase.h>
#include <Iphlpapi.h>
#include <stdlib.h>
#include <shlobj.h>
#include <shlwapi.h>
#include <WinIoCtl.h>
#pragma comment(lib, "IPHLPAPI.lib")
////////////////////////////////////////
#include <icmpapi.h>
#pragma comment(lib, "ws2_32.lib")
#include <iostream>
#include <strsafe.h>
//////////////////////////////////////
//for WMI
#define _WIN32_DCOM
#include <iostream>
using namespace std;
#include <wbemidl.h>
#pragma comment(lib, "wbemuuid.lib")
/////////////////////////////
#include <sstream>
#include <vector>
#include <algorithm>
#include <conio.h>
std::string WMI_Initialize(IWbemServices **pSvc, IWbemLocator **pLoc)
{
//Initialize COM.
HRESULT hr;
hr = CoInitializeEx(0, COINIT_MULTITHREADED);
if (FAILED(hr))
{
std::string result;
std::ostringstream out;
out << "Failed to initialize COM library. Error code = 0x"
<< hex << hr << endl;
result = out.str();
return result;
}
hr = CoInitializeSecurity(
NULL, // Security descriptor
-1, // COM negotiates authentication service
NULL, // Authentication services
NULL, // Reserved
RPC_C_AUTHN_LEVEL_DEFAULT, // Default authentication level for proxies
RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation level for proxies
NULL, // Authentication info
EOAC_NONE, // Additional capabilities of the client or server
NULL); // Reserved
if (FAILED(hr))
{
std::string result;
std::ostringstream out;
out << "Failed to initialize security. Error code = 0x"
<< hex << hr << endl;
CoUninitialize();
result = out.str();
return result;
}
hr = CoCreateInstance(CLSID_WbemLocator, 0,
CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *)&pLoc[0]);
if (FAILED(hr))
{
string result;
std::ostringstream out;
out << "Failed to create IWbemLocator object. Err code = 0x"
<< hex << hr << endl;
result = out.str();
CoUninitialize();
return result;
}
// Connect to the root\default namespace with the current user.
hr = (*pLoc)->ConnectServer(
BSTR(L"\\\\.\\root\\CIMV2"),
NULL, // User name
NULL, // User password
0, // Locale
NULL, // Security flags
0, // Authority
0, // Context object
&pSvc[0]); // IWbemServices proxy
// The rest/other stuffs below
}
And this is the calling function
std::string WMI_getHDDSN(std::string str)
{
IWbemServices *pSvc = NULL;
IWbemLocator *pLoc = NULL;
HRESULT hr;
std::string result = WMI_Initialize(&pSvc, &pLoc);
//The rest/other stuffs are below
}
And lastly the main function
int main(int argc, char *argv[])
{
std::wcout << "Press AnyKey" << std::endl;
std::string SN = WMI_getHDDSN("C");
std::wcout << "Error Message : " << SN.c_str() << std::endl;
_getch();
_getch();
}
Thank you very much.