.NET 3.x Копирование папки более 2ГБ с отображением прогресса в ProgressBar - Visual Basic .NET

Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows.Forms
Imports System.IO
 
Partial Public Class Form1
    Inherits Form
    Private maxbytes As Integer = 0
    Private copied As Integer = 0
    Private total As Integer = 0
    Private otkuda As String = "c:\My downloads\"
    Private kuda As String = "c:\Install\" + Date.Today + "\My downloads\"
 
    Public Sub New()
        InitializeComponent()
    End Sub
 
    Public Sub Copy1(sourceDirectory As String, targetDirectory As String)
 
        Dim diSource As New DirectoryInfo(sourceDirectory)
        Dim diTarget As New DirectoryInfo(targetDirectory)
        'Получает размер всех файлов, присутствующих в исходной папке.
        GetSize(diSource, diTarget)
        maxbytes = maxbytes \ 1024
 
        ProgressBar1.Maximum = maxbytes
        CopyAll(diSource, diTarget)
    End Sub
 
    Public Sub CopyAll(source As DirectoryInfo, target As DirectoryInfo)
 
        If Directory.Exists(target.FullName) = False Then
            Directory.CreateDirectory(target.FullName)
        End If
 
        For Each fi As FileInfo In source.GetFiles()
            fi.CopyTo(Path.Combine(target.ToString(), fi.Name), True)
 
            total += CInt(fi.Length)
 
            copied += CInt(fi.Length)
            copied /= 1024
            ProgressBar1.[Step] = copied
 
            ProgressBar1.PerformStep()
            label1.Text = (total \ 1048576).ToString() & "MB of " & (maxbytes \ 1024).ToString() & "MB copied"
 
            label1.Refresh()
        Next
 
        For Each diSourceSubDir As DirectoryInfo In source.GetDirectories()
            Dim nextTargetSubDir As DirectoryInfo = target.CreateSubdirectory(diSourceSubDir.Name)
            CopyAll(diSourceSubDir, nextTargetSubDir)
        Next
    End Sub
    Public Sub GetSize(source As DirectoryInfo, target As DirectoryInfo)
        If Directory.Exists(target.FullName) = False Then
            Directory.CreateDirectory(target.FullName)
        End If
        For Each fi As FileInfo In source.GetFiles()
            'Размер файла
            maxbytes += CInt(fi.Length)
        Next
        For Each diSourceSubDir As DirectoryInfo In source.GetDirectories()
            Dim nextTargetSubDir As DirectoryInfo = target.CreateSubdirectory(diSourceSubDir.Name)
            GetSize(diSourceSubDir, nextTargetSubDir)
        Next
 
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Copy1(otkuda, kuda)
        MessageBox.Show("Готово")
    End Sub
End Class