Is there a way to kill a critical process in C#?

In C#, i want to kill a critical process, like wininit.exe, services.exe or csrss.exe. This is the code i tried, which doesn't work. (Obliviously i run as admin).

static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            KillCriticalProcess(Process.GetProcessesByName("wininit")[0]);
        }

        [DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(uint processAccess, bool bInheritHandle, int processId);

        [DllImport("kernel32.dll")]
        private static extern bool TerminateProcess(IntPtr hProcess, int exitCode);

        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(IntPtr hObject);

        [DllImport("ntdll.dll")]
        private static extern int NtSetInformationProcess(IntPtr hProcess, int processInformationClass, ref int processInformation, int processInformationLength);

        private static uint PROCESS_TERMINATE = 0x00000001;
        private static uint PROCESS_SET_INFORMATION = 0x00000200;
        public static void KillCriticalProcess(Process proc)
        {
            IntPtr procHandle = OpenProcess(PROCESS_TERMINATE | PROCESS_SET_INFORMATION, false, proc.Id);
            int critical = 0;
            int BreakOnTermination = 0x1D;
            NTSTATUS ntStatus = NtSetInformationProcess(procHandle, BreakOnTermination, ref critical, sizeof(int));
            Console.WriteLine("ntstatus message: " + ntStatus);
            Console.WriteLine(TerminateProcess(procHandle, 0));
            CloseHandle(procHandle);
        }
    }

The problem is that nothing happens to wininit.exe (because there is no BSOD and i can see it in process hacker). NtSetInformationProcess returns STATUS_INVALID_HANDLE and TerminateProcess returns false. I wanna remember you again that i run as admin. This surely can be done just because processhacker can do this by running as user.