CreateProcess и SendMessage под Windows 10

int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
    HWND hwndMain = FindWindow(NULL, L"SU Wallpaper Changer");
    if (hwndMain) {
 
        HWND hwnd = FindWindowEx(hwndMain, NULL, NULL, L"Change now.");
        if (hwnd) PostMessage(hwnd, BM_CLICK, (WPARAM)NULL, (LPARAM)NULL);
        else { MessageBox(NULL, L"Not find Button", L"Error", MB_OK | MB_ICONSTOP); }
    }
    else {
        STARTUPINFO si;
        ZeroMemory(&si, sizeof(STARTUPINFO));
        PROCESS_INFORMATION pi;
 
        si.cb = sizeof(STARTUPINFO);
        si.dwFlags = STARTF_USESHOWWINDOW;
        si.wShowWindow = SW_MINIMIZE;
 
        TCHAR czCommandLine[] = L"C:\\Program Files\\Suwalls\\suwalls";
        CreateProcess(NULL, czCommandLine, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
    }
    return 0;
}

        TCHAR czCommandLine[] = L"C:\\Program Files\\Suwalls\\suwalls";
        CreateProcess(NULL, czCommandLine, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
        int Error = GetLastError();
 
        std::ofstream fout("error.txt"); 
        fout << Error;
        fout.close();

TCHAR czCommandLine[] = L"\"C:\\Program Files\\Suwalls\\suwalls.exe\"";