int GetUserName(char* szUserName)

{

#ifdef _DEBUG
CHAR szEchoStr[256];
#endif
DWORD nCount = 0;
HRESULT hres;
// Initialize COM.
hres = CoInitialize(NULL);
if (FAILED(hres))
{
#ifdef _DEBUG
sprintf(szEchoStr, "CoInitiaLize: %x", hres);
OutputDebugString(szEchoStr);
#endif
return 1; // Program has failed.
}

// Initialize
hres = CoInitializeSecurity(
NULL,
-1, // COM negotiates service
NULL, // Authentication services
NULL, // Reserved
RPC_C_AUTHN_LEVEL_DEFAULT, // authentication
RPC_C_IMP_LEVEL_IMPERSONATE, // Impersonation
NULL, // Authentication info
EOAC_NONE, // Additional capabilities
NULL // Reserved
);
if (FAILED(hres))
{
if(hres != RPC_E_TOO_LATE)
{
#ifdef _DEBUG
sprintf(szEchoStr, "CoInitializeSecurity: %x", hres);
OutputDebugString(szEchoStr);
#endif
CoUninitialize();
return 1;
}
}

// Obtain the initial locator to Windows Management
// on a particular host computer.
IWbemLocator *pLoc = 0;

hres = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLoc);
if (FAILED(hres))
{
#ifdef _DEBUG
sprintf(szEchoStr, "CoCreateInstance: %x", hres);
OutputDebugString(szEchoStr);
#endif
CoUninitialize();
return 1; // Program has failed.
}

IWbemServices *pSvc = 0;
hres = pLoc->ConnectServer(
_bstr_t(L"ROOT\\CIMV2"), // WMI namespace
NULL, // User name
NULL, // User password
0, // Locale
NULL, // Security flags
0, // Authority
0, // Context object
&pSvc // IWbemServices proxy
);
if (FAILED(hres))
{
#ifdef _DEBUG
sprintf(szEchoStr, "ConnectServer: %x", hres);
OutputDebugString(szEchoStr);
#endif
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}

// Set the IWbemServices proxy so that impersonation
// of the user (client) occurs.
hres = CoSetProxyBlanket(

pSvc, // the proxy to set
RPC_C_AUTHN_WINNT, // authentication service
RPC_C_AUTHZ_NONE, // authorization service
NULL, // Server principal name
RPC_C_AUTHN_LEVEL_CALL, // authentication level
RPC_C_IMP_LEVEL_IMPERSONATE, // impersonation level
NULL, // client identity
EOAC_NONE // proxy capabilities
);

if (FAILED(hres))
{
#ifdef _DEBUG
sprintf(szEchoStr, "CoSetProxyBlanket: %x", hres);
OutputDebugString(szEchoStr);
#endif
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}
//
IEnumWbemClassObject* pEnumerator = NULL;

hres = pSvc->ExecQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM Win32_ComputerSystem"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);
if (FAILED(hres))
{
#ifdef _DEBUG
sprintf(szEchoStr, "ExecQuery: %x", hres);
OutputDebugString(szEchoStr);
#endif
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}
else
{
IWbemClassObject *pclsObj;
ULONG uReturn = 0;
char *pstrResult = NULL;

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

if(0 == uReturn)
{
break;
}