Mir3/TestProcess/Form1.cs

using System;
using System.Diagnostics;
using System.Windows.Forms;

namespace TestProcess
{

    public static class ProcessExtensions
    {
        private static string FindIndexedProcessName(int pid)
        {
            var processName = Process.GetProcessById(pid).ProcessName;
            var processesByName = Process.GetProcessesByName(processName);
            string processIndexdName = null;
            for (var index = 0; index < processesByName.Length; index++)
            {
                processIndexdName = index == 0 ? processName : processName + "#" + index;
                var processId = new PerformanceCounter("Process", "ID Process", processIndexdName);
                if ((int)processId.NextValue() == pid)
                {
                    return processIndexdName;
                }
            }
            return processIndexdName;
        }

        private static Process FindPidFromIndexedProcessName(string indexedProcessName)
        {
            var parentId = new PerformanceCounter("Process", "Creating Process ID", indexedProcessName);
            return Process.GetProcessById((int)parentId.NextValue());
        }

        public static Process Parent(this Process process)
        {
            return FindPidFromIndexedProcessName(FindIndexedProcessName(process.Id));
        }
    }


    public partial class Form1 : Form
    {



        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string sysdir = Environment.GetFolderPath(Environment.SpecialFolder.System);
            MessageBox.Show(sysdir);

            string pfile = Process.GetCurrentProcess().Parent().ProcessName;
            MessageBox.Show(pfile);
        }
    }
}