Shutdown windows service

Imports System.IO
Imports System.Timers
Public Class OutlookService

    Protected Overrides Sub OnStart(ByVal args() As String)
        ' Inserire qui il codice necessario per avviare il proprio servizio. Il metodo deve effettuare
        ' le impostazioni necessarie per il funzionamento del servizio.
        AddHandler Microsoft.Win32.SystemEvents.SessionEnded, AddressOf OnSessionEnded

        Dim swc_log As Boolean
        Dim ws_ini As New iniParser("C:\UsrPrograms\OutlookService\OutlookService.ini")
        swc_log = Boolean.Parse(ws_ini.getValue("GENERALE", "SWC_LOG"))
        ws_log = New Log(swc_log)

        ws_server = ws_ini.getValue("GENERALE", "SERVER")
        ws_username = ws_ini.getValue("GENERALE", "USER_NAME")
        ws_password = ws_ini.getValue("GENERALE", "USER_PWD")
        ws_database = ws_ini.getValue("GENERALE", "DATABASE")

        ws_OSQL = New OutlookSQL()
        If ws_OSQL.ConnectDb(ws_server, ws_username, ws_password, ws_database) Then

            ws_iniDb = New IniParserDB
            PathDocuments = ws_iniDb.getParam("GENERALE", "PATH_DOCUMENTS").getValore
            PathDropbox = ws_iniDb.getParam("GENERALE", "PATH_DROPBOX").getValore
            TempDir = ws_iniDb.getParam("GENERALE", "TEMP_DIR").getValore

            Try
                Boolean.TryParse(ws_iniDb.getParam("GENERALE", "DEBUG").getValore, swc_debug)
            Catch ex As Exception
                swc_debug = False
            End Try

            ws_timer = New Timer()
            AddHandler ws_timer.Elapsed, AddressOf OnTimedEvent
            ws_timer.Interval = CDbl(ws_iniDb.getParam("GENERALE", "INTERVAL").getValore) * 1000
            ws_timer.Enabled = True
        End If

    End Sub
    Private Sub OnSessionEnded()
        ws_log.ScriviLog("Windows Shutdown - Stop Service")
        Me.Stop()
    End Sub

    Protected Overrides Sub OnShutdown()
        Me.Stop()
    End Sub

    Protected Overrides Sub OnStop()
        ws_timer.Enabled = False

        ws_OSQL.Dispose()
        ws_OSQL = Nothing

        ws_log.Flush()
        ws_log.Dispose()
        ws_log = Nothing
    End Sub

    Private Sub OnTimedEvent()

        ws_log.ScriviLog("Try to analize files in: " & TempDir)
        For Each myFilename In Directory.GetFiles(TempDir)
            ws_log.ScriviLog("  Found file to elaborate: " & myFilename)
            Dim OutEng As New OutlookEngine(myFilename)
        Next

    End Sub