public string GetProcessOwner(int processId)
{
    string query = "Select * From Win32_Process Where ProcessID = " + processId;
    ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
    ManagementObjectCollection processList = searcher.Get();

    foreach (ManagementObject obj in processList)
    {
        string[] argList = new string[] { string.Empty, string.Empty };
        int returnVal = Convert.ToInt32(obj.InvokeMethod("GetOwner", argList));
        if (returnVal == 0)
        {
            // return DOMAINuser
            return argList[1] + "\" + argList[0];
        }
    }

    return "NO OWNER";
}

public string GetProcessOwner(string processName)
{
    string query = "Select * from Win32_Process Where Name = "" + processName + """;
    ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
    ManagementObjectCollection processList = searcher.Get();

    foreach (ManagementObject obj in processList)
    {
        string[] argList = new string[] { string.Empty, string.Empty };
        int returnVal = Convert.ToInt32(obj.InvokeMethod("GetOwner", argList));
        if (returnVal == 0)
        {
            // return DOMAINuser
            string owner = argList[1] + "\" + argList[0];
            return owner;
        }
    }

    return "NO OWNER";
}

List<string> sp = new List<string>
{
    "svchost", "csrss", "System", "wininit",
    "irstrtsv","scrncap","lsass","System",
    "wininit","taskmgr","dwm","spoolsv","smss",
    "SearchIndexer","lsm","taskhost","svchost","explorer",
    "winlogon","services","conhost"
};

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;
using System.Diagnostics;
using System.Windows.Forms;

namespace WindowsFormsTest1
{
    public partial class Form1 : Form
    {

        [DllImport("Rstrtmgr.dll", CharSet = CharSet.Unicode, PreserveSig = true, SetLastError = true, ExactSpelling = true)]
        public static extern UInt32 RmStartSession(out UInt32 pSessionHandle, UInt32 dwSessionFlags,
            string strSessionKey);

        [DllImport("Rstrtmgr.dll", CharSet = CharSet.Unicode, PreserveSig = true, SetLastError = true, ExactSpelling = true)]
        public static extern UInt32 RmRegisterResources(UInt32 dwSessionHandle,
        UInt32 nFiles, string[] rgsFilenames, UInt32 nApplications,
        ref RM_UNIQUE_PROCESS rgApplications, UInt32 nServices, string[] rgsServiceNames);

        [DllImport("Rstrtmgr.dll", CharSet = CharSet.Unicode, PreserveSig = true, SetLastError = true, ExactSpelling = true)]
        public static extern UInt32 RmGetList(UInt32 dwSessionHandle, out UInt32 pnProcInfoNeeded,
        ref UInt32 pnProcInfo, [In, Out] RM_PROCESS_INFO[] rgAffectedApps, ref UInt32 lpdwRebootReasons);

        [DllImport("Rstrtmgr.dll", CharSet = CharSet.Unicode, PreserveSig = true, SetLastError = true, ExactSpelling = true)]
        public static extern UInt32 RmEndSession(UInt32 dwSessionHandle);

        public const UInt32 RmRebootReasonNone = 0x0;
        public const int ERROR_MORE_DATA = 234;

        /// <summary>
        /// Преобразование DateTime в структуру FILETIME
        /// </summary>
        public static System.Runtime.InteropServices.ComTypes.FILETIME FileTimeFromDateTime(DateTime date)
        {
            long ftime = date.ToFileTime();
            System.Runtime.InteropServices.ComTypes.FILETIME ft = new System.Runtime.InteropServices.ComTypes.FILETIME();
            ft.dwHighDateTime = (int)(ftime >> 32);
            ft.dwLowDateTime = (int)ftime;
            return ft;
        }

        /// <summary>
        /// Получение типа процесса
        /// </summary>
        public static RM_APP_TYPE GetProcessType(Process proc)
        {
            uint handle;
            string key = Guid.NewGuid().ToString();

            uint res = RmStartSession(out handle, (uint)0, key);
            if (res != 0)
            {
                throw new ApplicationException("Could not begin restart session. ");
            }

            try
            {
                uint pnProcInfoNeeded = 0, pnProcInfo = 0,
                    lpdwRebootReasons = RmRebootReasonNone;

                RM_UNIQUE_PROCESS uniqueprocess = new RM_UNIQUE_PROCESS();
                uniqueprocess.dwProcessId = proc.Id;
                System.Runtime.InteropServices.ComTypes.FILETIME ft = FileTimeFromDateTime(proc.StartTime);
                uniqueprocess.ProcessStartTime = ft;

                res = RmRegisterResources(handle, 0, null, 1, ref uniqueprocess, 0, null);

                if (res != 0)
                {
                    throw new ApplicationException("Could not register resource.");
                }

                res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, null,
                                ref lpdwRebootReasons);
                if (res == ERROR_MORE_DATA)
                {
                    RM_PROCESS_INFO[] processInfo = new RM_PROCESS_INFO[pnProcInfoNeeded];
                    pnProcInfo = pnProcInfoNeeded;

                    // Get the list.
                    res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo,
                        processInfo, ref lpdwRebootReasons);
                    if (res == 0)
                    {
                        if (pnProcInfo == 0) throw new ApplicationException("Process not found");

                        return processInfo[0].ApplicationType;
                    }
                    else
                    {
                        throw new ApplicationException("Could not list processes");
                    }
                }
                else if (res != 0)
                {
                    throw new ApplicationException("Failed to get size of result.");
                }
            }
            finally
            {
                RmEndSession(handle);
            }
            throw new ApplicationException("Process not found");
        }


        public Form1()
        {
            InitializeComponent();
        }


        private void button1_Click(object sender, EventArgs e)
        {
            //пример использования
            Process p=Process.GetProcessesByName(textBox1.Text)[0];
            MessageBox.Show(GetProcessType(p).ToString());
            /*Для системных процессов выведет RmCritical*/
        }
    }

    /* Определения структур */

    [StructLayout(LayoutKind.Sequential)]
    public struct RM_UNIQUE_PROCESS
    {
        // The product identifier (PID).
        public int dwProcessId;
        // The creation time of the process.
        public System.Runtime.InteropServices.ComTypes.FILETIME ProcessStartTime;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct RM_PROCESS_INFO
    {
        const int CCH_RM_MAX_APP_NAME = 255;
        const int CCH_RM_MAX_SVC_NAME = 63;

        // Contains an RM_UNIQUE_PROCESS structure that uniquely identifies the
        // application by its PID and the time the process began.
        public RM_UNIQUE_PROCESS Process;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_APP_NAME + 1)]
        // If the process is a service, this parameter returns the
        // long name for the service.
        public string strAppName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_SVC_NAME + 1)]
        // If the process is a service, this is the short name for the service.
        public string strServiceShortName;
        // Contains an RM_APP_TYPE enumeration value.
        public RM_APP_TYPE ApplicationType;
        // Contains a bit mask that describes the current status of the application.
        public uint AppStatus;
        // Contains the Terminal Services session ID of the process.
        public uint TSSessionId;
        // TRUE if the application can be restarted by the
        // Restart Manager; otherwise, FALSE.
        [MarshalAs(UnmanagedType.Bool)]
        public bool bRestartable;
    }

    public enum RM_APP_TYPE
    {
        // The application cannot be classified as any other type.
        RmUnknownApp = 0,
        // A Windows application run as a stand-alone process that
        // displays a top-level window.
        RmMainWindow = 1,
        // A Windows application that does not run as a stand-alone
        // process and does not display a top-level window.
        RmOtherWindow = 2,
        // The application is a Windows service.
        RmService = 3,
        // The application is Windows Explorer.
        RmExplorer = 4,
        // The application is a stand-alone console application.
        RmConsole = 5,
        // A system restart is required to complete the installation because
        // a process cannot be shut down.
        RmCritical = 1000
    }
}

Process[] processList = Process.GetProcesses();
foreach (Process process in processList)
{
    // В process хранится информация о процессе
}

public static List<KeyValuePair<int, string>> GetProcessExtraInformation(int processId)
{
    // запрос получения всех процессов связанных с переданным идентификатором processId
    string query = "Select * From Win32_Process Where ProcessID = " + processId;
    ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
    ManagementObjectCollection processList = searcher.Get();

    // здесь будет результат
    List<KeyValuePair<int, string>> result = new List<KeyValuePair<int, string>>();

    foreach (ManagementObject obj in processList)
    {
        var description = @"Не могу получить информацию о процессе";
        // Получим описание процесса, если таковое имеется
        if (obj["ExecutablePath"] != null)
        {
            try
            {
                FileVersionInfo info = FileVersionInfo.GetVersionInfo(obj["ExecutablePath"].ToString());
                description = info.FileDescription;
            }
            catch { }
        }

        // Получить владельца процесса в argList
        var owner = @"Не могу получить владельца процесса";
        string[] argList = new string[] { string.Empty, string.Empty };
        int returnVal = Convert.ToInt32(obj.InvokeMethod("GetOwner", argList));
        if (returnVal == 0)
        {
            owner = argList[1] + "\" + argList[0]; // Домен и владелец
        }

        result.Add(new KeyValuePair<int, string>(processId, string.Format("Description: '{0}'nOwner: '{1}'", description, owner)));
    }

    return result;
}

Process[] processList = Process.GetProcesses();
foreach (Process process in processList)
{
    // В process хранится информация о процессе
    var processInfo = GetProcessExtraInformation(process.Id);

    foreach (var info in processInfo)
    {
        Console.WriteLine(string.Format("Id: {0}n{1}", info.Key, info.Value));
    }
    Console.WriteLine();
}

Console.ReadLine();