Sample of a Manager with Singleton to execute command on windows shell

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

namespace Framework
{
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    /// <summary>   Manager shell. </summary>
    ////////////////////////////////////////////////////////////////////////////////////////////////////

    public class ManagerShell
    {
        
        #region Gestion du singleton

        /// <summary>   The instance. </summary>
        private static ManagerShell instance = null;
        /// <summary>   The padlock. </summary>
        private static readonly object padlock = new object();

        ////////////////////////////////////////////////////////////////////////////////////////////////////
        /// <summary>
        /// Prevents a default instance of the <see cref="ManagerShell"/> class from being created.
        /// </summary>
        ////////////////////////////////////////////////////////////////////////////////////////////////////

        ManagerShell()
        {
            //if (_Log.IsDebugEnabled)
            // _Log.DebugFormat("New instance of {0}", Assembly.GetExecutingAssembly());
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////////
        /// <summary>   Gets the instance. </summary>
        ///
        /// <value> The instance. </value>
        ////////////////////////////////////////////////////////////////////////////////////////////////////

        public static ManagerShell Instance
        {
            get
            {
                lock (padlock)
                {
                    if (instance == null)
                    {
                        instance = new ManagerShell();
                    }
                    return instance;
                }
            }
        }
        #endregion Gestion du singleton

        ////////////////////////////////////////////////////////////////////////////////////////////////////
        /// <summary>   Invokes the prompt. (silently) </summary>
        ///
        /// <param name="Command">  The command. </param>
        ///
        /// <returns>   true if it succeeds, false if it fails. </returns>
        ////////////////////////////////////////////////////////////////////////////////////////////////////

        public bool InvokePrompt(string command)
        {
            if (String.IsNullOrEmpty(command))
                throw new ArgumentNullException("command");

            try
            {
                Process invokePrompt = new Process();
                invokePrompt.StartInfo.FileName = Environment.GetEnvironmentVariable("COMSPEC");
                invokePrompt.StartInfo.Arguments = "/Q /K /C " + command;
                invokePrompt.StartInfo.UseShellExecute = false;
                invokePrompt.StartInfo.RedirectStandardOutput = false;
                invokePrompt.StartInfo.CreateNoWindow = true;
                invokePrompt.Start();
                invokePrompt.WaitForExit();
                invokePrompt.Close();
                return true;
            }
            catch (Exception ex)
            {              
                return false;
            }
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////////
        /// <summary>   Invokes the process. (silently) </summary>
        ///
        ///
        /// <param name="ProcessName">  Name of the process. </param>
        /// <param name="Command">      The command. </param>
        ///
        /// <returns>   true if it succeeds, false if it fails. </returns>
        ////////////////////////////////////////////////////////////////////////////////////////////////////

        public bool InvokeProcess(string processName, string command)
        {
            if (String.IsNullOrEmpty(processName))
                throw new ArgumentNullException("processName");

            if (String.IsNullOrEmpty(command))
                throw new ArgumentNullException("command"); 
            try
            {
                Process invokeProcess = new Process();
                invokeProcess.StartInfo.FileName = processName;
                invokeProcess.StartInfo.Arguments = command;
                invokeProcess.StartInfo.UseShellExecute = false;
                invokeProcess.StartInfo.RedirectStandardOutput = false;
                invokeProcess.StartInfo.CreateNoWindow = true;
                invokeProcess.Start();
                invokeProcess.WaitForExit();
                invokeProcess.Close();
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
        }
    }
}