Windows Embedded does not honor ShutdownBlockReasonCreate - windows

Question

The following program works on Windows 7 but not on Windows 7 Embedded Standard Service Pack 1. It does not prevent the shutdown (e.g. shutdown /r /t 0) from happening.
This is a similar question as the one which is linked as duplicate. But that question has the accepted answer of "it does not work". I also provide sourcecode to a working solution in Windows 7 which just needs some adjustment for Windows Embedded.
Any ides how to get it working on Embedded? Or at least a hint where the Windows Docu points that difference out?
#include <windows.h>
#include <stdio.h>
const char g_szClassName[] = "myWindowClass";
// Step 6: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_QUERYENDSESSION:
OutputDebugStr("Got WM_QUERYENDSESSION message\n");
char buf[1024];
sprintf(buf, "Callback %d %d\n", wParam, lParam);
OutputDebugStr(buf);
return FALSE; // FALSE should prevent reboot
break;
case WM_ENDSESSION:
OutputDebugStr("Got WM_ENDSESSION message\n");
Sleep(5000); // Should never get here!
break;
case WM_CLOSE:
OutputDebugStr("Got WM_CLOSE message\n");
DestroyWindow(hwnd);
break;
case WM_DESTROY:
OutputDebugStr("Got WM_DESTROY message\n");
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;
//Step 1: Registering the Window Class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if(!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
// Step 2: Creating the Window
hwnd = CreateWindowEx(
WS_EX_CLIENTEDGE,
g_szClassName,
"The title of my window",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, 240, 120,
NULL, NULL, hInstance, NULL);
if(hwnd == NULL)
{
MessageBox(NULL, "Window Creation Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// Step 3: We provide a reason for the shutdown prevention
BOOL ret = ShutdownBlockReasonCreate(hwnd, L"PreventShutdown running which prevents shutdown");
if(ret == FALSE)
{
MessageBox(NULL, "ShutdownBlockReasonCreate Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
// Step 4: We elevate the program to be asked as soon as possible to inhibit shutdown
ret = SetProcessShutdownParameters(0x4FF, SHUTDOWN_NORETRY)
if(ret == FALSE)
{
MessageBox(NULL, "ShutdownBlockReasonCreate Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
OutputDebugStr("Now starting message loop\n");
// Step 5: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return Msg.wParam;
}

Answer 1

We already have a canonical answer for this question, you'll find it here. Seven hundred views and half a year of researching this make this the best known answer, it can't be done.
Keep an eye on your existing question on the MSDN Forums.
I'll close with a few graphical explanations why this kind of feature is not implemented on an embedded operating system: