Dim Reader As New BinaryReader(File.OpenRead(Source))
        Dim Writer As New BinaryWriter(File.Create(Target))
        Dim B As Integer = TextBox1.Text
        ProgressBar1.Maximum = Reader.BaseStream.Length
        While Reader.BaseStream.Position < Reader.BaseStream.Length
            Writer.Write(Reader.ReadBytes(B))
            ProgressBar1.Value = Reader.BaseStream.Position
            Me.Refresh()
            If k = True Then
                GoTo 10
            End If
        End While
10:     Reader.Close()
        Writer.Flush() : Writer.Close()
        k = False

Dim k as Boolean=False