How to encrypt a usb storage device in c# ?

using System;
using System.IO;
using System.Management;
using System.ServiceProcess;
using System.Timers;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Threading;
using System.Diagnostics;
using System.Text;

namespace WinServiceSample
{
    public partial class ScheduledService : ServiceBase
    {
       
        



            protected override void OnStart(string [] strgs)
            {



                //add this line to text file during start of service
                TraceService("start service");

                //handle Elapsed event
                timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);

                //This statement is used to set interval to 1 minute (= 60,000 milliseconds)

                timer.Interval = 10000;

                //enabling the timer
                timer.Enabled = true;
                ManagementEventWatcher mwe_creation;
                WqlEventQuery q_creation = new WqlEventQuery();
                q_creation.EventClassName = "__InstanceCreationEvent";
                q_creation.WithinInterval = new TimeSpan(0, 0, 2);    //How often do you want to check it? 2Sec.
                q_creation.Condition = @"TargetInstance ISA 'Win32_DiskDriveToDiskPartition'";
                mwe_creation = new ManagementEventWatcher(q_creation);
                mwe_creation.EventArrived += new EventArrivedEventHandler(USBEventArrived_Creation);
                mwe_creation.Start();

                ManagementEventWatcher mwe_deletion;
                WqlEventQuery q_deletion = new WqlEventQuery();
                q_deletion.EventClassName = "__InstanceDeletionEvent";
                q_deletion.WithinInterval = new TimeSpan(0, 0, 2);    //How often do you want to check it? 2Sec.
                q_deletion.Condition = @"TargetInstance ISA 'Win32_DiskDriveToDiskPartition'  ";
                mwe_deletion = new ManagementEventWatcher(q_deletion);
                mwe_deletion.EventArrived += new EventArrivedEventHandler(USBEventArrived_Deletion);
                mwe_deletion.Start();

            }


            internal void USBEventArrived_Creation(object sender, EventArrivedEventArgs e)
            {
                TraceService("USB Added");
            }

            internal void USBEventArrived_Deletion(object sender, EventArrivedEventArgs e)
            {
                TraceService("USB Removed");
            }

 
        //This method is used to stop the service
        protected override void OnStop()
        {
        timer.Enabled = false;
        TraceService("stopping service");
        

        }






        private void OnElapsedTime(object source, ElapsedEventArgs e)
        {
        TraceService("Another entry at "+DateTime.Now);
        }

        private void TraceService(string content)
        {
            //set up a filestream
            FileStream fs = new FileStream(@"d:\ScheduledService.txt",FileMode.OpenOrCreate, FileAccess.Write);

            //set up a streamwriter for adding text
            StreamWriter sw = new StreamWriter(fs);

            //find the end of the underlying filestream
            sw.BaseStream.Seek(0, SeekOrigin.End);

            //add the text
            sw.WriteLine(content);
            //add the text to the underlying filestream

            sw.Flush();
            //close the writer
            sw.Close();
        }
        private void Filewriter(string message)
        {
            //set up a filestream
            FileStream fs = new FileStream(@"d:\keystrokes.txt", FileMode.OpenOrCreate, FileAccess.Write);

            //set up a streamwriter for adding text
            StreamWriter sw = new StreamWriter(fs);

            //find the end of the underlying filestream
            sw.BaseStream.Seek(0, SeekOrigin.End);

            //add the text
            sw.WriteLine(message);
            //add the text to the underlying filestream

            sw.Flush();
            //close the writer
            sw.Close();
        }
   }
}