windows service start a interactive process(MFC application) on Windows XP - c++

Question

now I have a windows service, and I want the service create a GUI process(MFC application). And I referenced the code:Launch your application in Vista under the local system account without the UAC popup .
And the important is :
PROCESS_INFORMATION pi;
STARTUPINFO si;
BOOL bResult = FALSE;
DWORD dwSessionId,winlogonPid;
HANDLE hUserToken,hUserTokenDup,hPToken,hProcess;
DWORD dwCreationFlags;
// Log the client on to the local computer.
dwSessionId = WTSGetActiveConsoleSessionId();
WTSQueryUserToken(dwSessionId,&hUserToken);
dwCreationFlags = NORMAL_PRIORITY_CLASS|CREATE_NEW_CONSOLE;
ZeroMemory(&si, sizeof(STARTUPINFO));
si.cb= sizeof(STARTUPINFO);
si.lpDesktop = "winsta0\\default";
ZeroMemory(&pi, sizeof(pi));
TOKEN_PRIVILEGES tp;
LUID luid;
hProcess = OpenProcess(MAXIMUM_ALLOWED,FALSE,GetCurrentProcessId();
if(!::OpenProcessToken(hProcess,TOKEN_ADJUST_PRIVILEGES|TOKEN_QUERY
|TOKEN_DUPLICATE|TOKEN_ASSIGN_PRIMARY|TOKEN_ADJUST_SESSIONID
|TOKEN_READ|TOKEN_WRITE,&hPToken))
{
int abcd = GetLastError();
printf("Process token open Error: %u\n",GetLastError());
}
if (!LookupPrivilegeValue(NULL,SE_DEBUG_NAME,&luid))
{
printf("Lookup Privilege value Error: %u\n",GetLastError());
}
tp.PrivilegeCount =1;
tp.Privileges[0].Luid =luid;
tp.Privileges[0].Attributes =SE_PRIVILEGE_ENABLED;
DuplicateTokenEx(hPToken,MAXIMUM_ALLOWED,NULL,SecurityIdentification,TokenPrimary,&hUserTokenDup);
int dup = GetLastError();
//Adjust Token privilege
SetTokenInformation(hUserTokenDup,TokenSessionId,(void*)dwSessionId,sizeof(DWORD));
if (!AdjustTokenPrivileges(hUserTokenDup,FALSE,&tp,sizeof(TOKEN_PRIVILEGES),(PTOKEN_PRIVILEGES)NULL,NULL))
{
int abc =GetLastError();
printf("Adjust Privilege value Error: %u\n",GetLastError());
}
if (GetLastError()== ERROR_NOT_ALL_ASSIGNED)
{
printf("Token does not have the provilege\n");
}
LPVOID pEnv =NULL;
if(CreateEnvironmentBlock(&pEnv,hUserTokenDup,TRUE))
{
dwCreationFlags|=CREATE_UNICODE_ENVIRONMENT;
}
else
pEnv=NULL;
// Launch the process in the client's logon session.
bResult = CreateProcessAsUser(
hUserTokenDup, // client's access token
_T("TestDialog.exe"), // file to execute
NULL, // command line
NULL, // pointer to process SECURITY_ATTRIBUTES
NULL, // pointer to thread SECURITY_ATTRIBUTES
FALSE, // handles are not inheritable
dwCreationFlags, // creation flags
pEnv, // pointer to new environment block
NULL, // name of current directory
&si, // pointer to STARTUPINFO structure
&pi // receives information about new process
);
// End impersonation of client.
//GetLastError Shud be 0
int iResultOfCreateProcessAsUser = GetLastError();
//Perform All the Close Handles task
CloseHandle(hProcess);
CloseHandle(hUserToken);
CloseHandle(hUserTokenDup);
CloseHandle(hPToken);
return 0;
Now the MFC application can be started after the service stared, it works well. And the process user name is System.
But when I logoff my account(the GUI application is running while click the windows system logoff button), the MFC application have a VC++ crash, the crash point the MFC internal function afxactivationwndproc .
My MFC application is just created by the VS2010 IDE without modify.
My test environment is on Windows XP.
If I double click the application to run it, and logoff with the application running, no error occurs.
So I want to know:
When user logoff, will system force kill my MFC application process? (Note: The process user name is System)
As mentioned, if I double click the application to run it, it is OK. So is there any problem with the service starting method? Or we should add addition necessary operation to the MFC application.
Is there any other possible reason for this error?
Thank you very much!