Сканирование компьютеров в сети в отдельном потоке - Visual Basic .NET

        For Each item In ListBox1.Items
 
            Try
                If My.Computer.Network.Ping(item.ToString) Then
                    ListBox2.Items.Add(item.ToString)
                Else
                    ListBox3.Items.Add(item.ToString)
                    'MsgBox(item.ToString)
                End If
            Catch ex As Exception
                ListBox3.Items.Add(item.ToString)
                'MsgBox(item.ToString)
            End Try
        Next

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        If BackgroundWorker1.IsBusy = True Then
            Exit Sub
        Else
            BackgroundWorker1.RunWorkerAsync()
            'ProgressBar1.Visible = True
            ListBox2.Items.Clear()
            ListBox3.Items.Clear()
        End If

    End Sub
    Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        For Each item In ListBox1.Items
 
            Try
                If My.Computer.Network.Ping(item.ToString) Then
                    ListBox2.Items.Add(item.ToString)
                Else
                    ListBox3.Items.Add(item.ToString)
                End If
            Catch ex As Exception
                ListBox3.Items.Add(item.ToString)
            End Try
        Next
 
    End Sub
 
    Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
        ProgressBar1.Visible = False
  
    End Sub