How close message box after closing parent process opened using CreateProcess() - c++

Question

I want auto check bad or good for run my .exe files. For example for this binaries I have missing dll's, and when I use CreateProcess it's not return error and provide me system MessageBox("Dll is missing"). If I close it by hand, methods return exitCode STATUS_DLL_NOT_FOUND. I want that from some timeout all system message boxes will be closed with closing parent process and i can get my STATUS_DLL_NOT_FOUND. Me need full automatically work from my code.This code can closed opened sub dialogs, but can't close messageboxes.
int main()
{
HANDLE hJob;
JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli = { 0 };
PROCESS_INFORMATION pi = { 0 };
STARTUPINFO si = { 0 };
hJob = CreateJobObject(NULL, NULL);
jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
SetInformationJobObject(hJob, JobObjectExtendedLimitInformation, &jeli, sizeof(jeli));
TCHAR szCmdline[] = TEXT(" -R:mm");
si.cb = sizeof(si);
CreateProcess(
executableFiles[0].c_str(),
szCmdline,
NULL,
NULL,
FALSE,
CREATE_SUSPENDED | CREATE_BREAKAWAY_FROM_JOB /*Important*/,
NULL,
NULL,
&si,
&pi);
AssignProcessToJobObject(hJob, pi.hProcess); // Does not work if without CREATE_BREAKAWAY_FROM_JOB
ResumeThread(pi.hThread);
if (WaitForSingleObject(pi.hProcess, 3000) == WAIT_TIMEOUT)
{
EnumWindows(&SendWMCloseMsg, pi.dwProcessId);
if (WaitForSingleObject(pi.hProcess, 2000) == WAIT_TIMEOUT)
{
TerminateProcess(pi.hProcess, 0);
DWORD dwExitCode = 0;
GetExitCodeProcess(pi.hProcess, &dwExitCode);
const DWORD result = WaitForSingleObject(pi.hProcess, 2000);
if (result == WAIT_OBJECT_0)
{
if (dwExitCode == STATUS_DLL_NOT_FOUND)
{
std::cout << "Dll is missing" << std::endl;
}
}
else
{
std::cout << "bad case" << std::endl;
}
}
}
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
CloseHandle(hJob);
return 0;
}

Answer 1

Call UINT oldErrorMode = SetErrorMode(SEM_FAILCRITICALERRORS); before CreateProcess, and make sure that CREATE_DEFAULT_ERROR_MODE is not set in the dwCreationFlags parameter, so that the child process inherits the error mode of the parent. Per docs, this "does not display the critical-error-handler message box, instead, the system sends the error to the calling process".
Optionally SetErrorMode(oldErrorMode); after CreateProcess to restore the previous setting.