Почему мой filesystemwatcher использует так много ресурсов процессора? Vb.net

Private Sub FileSystemWatcher1_Renamed(ByVal sender As System.Object, ByVal e As System.IO.RenamedEventArgs) Handles FileSystemWatcher1.Renamed
       Dim OpenFileDialog3 As String
       Try
           Detect.Labellastreal.Text = e.FullPath
           ListBox3.Items.Add(Detect.Labellastreal.Text)
           OpenFileDialog3 = ""


           Dim md5 As New MD5CryptoServiceProvider
           Dim f As New FileStream(e.FullPath, FileMode.Open, FileAccess.Read, FileShare.Read, &H2000)
           md5.ComputeHash(f)
           Dim hash As Byte() = md5.Hash
           Dim buff As New StringBuilder
           Dim hashByte As Byte
           For Each hashByte In hash
               buff.Append(String.Format("{0:X2}", hashByte))
           Next
           f.Close()
           If My.Computer.FileSystem.ReadAllText(Application.StartupPath & "\Database\UnwantedProgs.txt").Contains(buff.ToString) Then
               OpenFileDialog3 = e.FullPath
               File.Move(Detect.Labellastreal.Text, Path.Combine("C:\ProgramData\DreamyTS\Infected\", Path.GetFileName(Detect.Labellastreal.Text)))
               Detect.ShowDialog()

               WriteToLog("Unwanted Program detected")
           End If

       Catch exception1 As Exception
           ProjectData.SetProjectError(exception1)
           Dim ex As Exception = exception1
           ProjectData.ClearProjectError()
       End Try
   End Sub