CreateProcess(...
   WaitForSingleObject(Process.hProcess, INFINITE

CreateProcess ...
do {
    Sleep(100);
    Res = WaitForSingleObject(Process.hProcess, 10);
} while (Res == WAIT_TIMEOUT);

MSG msg;
DWORD reason = WAIT_TIMEOUT;
while (WAIT_OBJECT_0 != reason) {
    reason = MsgWaitForMultipleObjects(1, &hChildProcess, FALSE, INFINITE, QS_ALLINPUT);
    switch (reason) {
    case WAIT_OBJECT_0:
        // Your child process is finished.
        break;
    case (WAIT_OBJECT_0 + 1):
        // A message is available in the message queue.
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
            // Note that if your main message loop does additional processing
            // (such as calling IsDialogMessage() for modeless dialogs)
            // you will want to do those things here, too.
        }
        break;
    }
}