Hide Window by CreateProcess WinApi

TomNow99

Hello,

I would like to hide qemu application and create application something like fsproxy. I find very interesting function WinApi "CreateProcess" and structure "STARTUPINFO". So i Wrote:

wchar_t qemu_args[2048] = L"\"C:\\Users\Tom\\Desktop\\apps\\qemu.exe (here args)\"";
wchar_t path[256]= L"C:\\Users\\Tom\\Desktop\\apps\\";

STARTUPINFO si;
memset(&si, 0, sizeof(STARTUPINFO));
GetStartupInfo(&si);
si.dwFlags	   = STARTF_USESHOWWINDOW;
si.wShowWindow = SW_HIDE;

CreateProcess(NULL, qemu_args, NULL, NULL, FALSE, 0, NULL, path, &si, &xa);

When I set si (dwFlags and wShowWindow) I get 2 windows: myQTApplication ( xyz.exe ) and qemu
When I don't set si I get 3 windows: myQTApplication ( xyz.exe ), qemu and consoleWindow (its name is pathToBuildXYZexe)

So si structure only hide that ConsoleWindow ( pathToBuildXYZexe ).

I know that I can get hmnd to qemu window by name and hide window, but I would like to do that when process is created.

And my second question is: Why I can't set the 8-th parameter ( path ) to NULL. When I give here NULL, QEMU don't start. I have to give path to qemu folder.

EDIT:
Now I wrote very basic console application in QT abc.exe:

#include <QCoreApplication>
#include <QDebug>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    qDebug()<<"1";
    return a.exec();
}

When I execute abc.exe from xyz.exe ( myMainQTGUIApplication ) by CreateProcess and when si is set I get 2 windows: xyz.exe and consoleWindow (its name is pathToBuildXYZexe) with text "1" ( this is output from abc.exe).
When I execute abc.exe from xyz.exe ( myMainQTGUIApplication ) by CreateProcess and when si isn't set I get 2 windows: xyz.exe and consoleWindow (its name is pathToBuildXYZexe) with notext.

EDIT2
Back to qemu. When I don't set si there are 3 windows. But when I close qemu, the window with name pathToBuildXYZexe is closed too. When I close pathToBuildXYZexe, qemu is closed too. In manager I see 2 processess: qemu and xyz.exe.

EDIT3
I think qemu is not hidden beacuse it's blocking terminal Application. But I think there is another solution...