hvordan kan jeg få mit program til at download 1 fil af gangen? VB.net

hej er i gang med at lave en download manager  med software som jeg selv laver i vb.net men hvis jeg har 3 downloads så downloader de samtidigt hvordan kan man få dem til at downloade 1 af gangen? når det er checkboxes. fx hvis der er 3 chekboxes og jeg vælger 2 checkboxes så for jeg 2 downloads med det valgte software som jeg har lavet hvordan hvis jeg vælger 3 checkboxes hvordan får jeg den til at download 1 af gangen?

code:

Imports System.Net



Public Class Form1

    Private WithEvents wc1 As New Net.WebClient
    Private WithEvents wc2 As New Net.WebClient
    Private WithEvents wc3 As New Net.WebClient
    Private q As New Queue

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim SFD As New SaveFileDialog
        If SFD.ShowDialog() = DialogResult.OK Then
            wc1.DownloadFileAsync(New Uri("https://dl.dropboxusercontent.com/u/185853590/client/update/minecraft.jar"), SFD.FileName)
        End If

    End Sub

    Private Sub wc1_DownloadFileCompleted(sender As Object, e As System.ComponentModel.AsyncCompletedEventArgs) Handles wc1.DownloadFileCompleted
        MsgBox("Done")
        ProgressBar1.Value = 0
    End Sub



    Private Sub wc1_DownloadProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs) Handles wc1.DownloadProgressChanged
        ProgressBar1.Maximum = e.TotalBytesToReceive
        ProgressBar1.Value = e.BytesReceived
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Dim SFD As New SaveFileDialog
        If SFD.ShowDialog() = DialogResult.OK Then
            wc2.DownloadFileAsync(New Uri("https://dl.dropboxusercontent.com/u/185853590/client/update/minecraft.jar"), SFD.FileName)
        End If
    End Sub

    Private Sub wc2_DownloadFileCompleted(sender As Object, e As System.ComponentModel.AsyncCompletedEventArgs) Handles wc2.DownloadFileCompleted
        MsgBox("Done")
        ProgressBar1.Value = 0
    End Sub

    Private Sub wc2_DownloadProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs) Handles wc2.DownloadProgressChanged
        ProgressBar1.Maximum = e.TotalBytesToReceive
        ProgressBar1.Value = e.BytesReceived
    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        If CheckBox1.Checked = True Then
            Dim SFD As New SaveFileDialog
            If SFD.ShowDialog() = DialogResult.OK Then
                wc1.DownloadFileAsync(New Uri("https://dl.dropboxusercontent.com/u/185853590/client/update/minecraft.jar"), SFD.FileName)
            End If
        End If

        If CheckBox2.Checked = True Then
            Dim SFD As New SaveFileDialog
            If SFD.ShowDialog() = DialogResult.OK Then
                wc2.DownloadFileAsync(New Uri("https://dl.dropboxusercontent.com/u/185853590/client/update/minecraft.jar"), SFD.FileName)
            End If
        End If

        If CheckBox3.Checked = True Then
            Dim SFD As New SaveFileDialog
            If SFD.ShowDialog() = DialogResult.OK Then
                wc3.DownloadFileAsync(New Uri("https://dl.dropboxusercontent.com/u/185853590/client/update/minecraft.jar"), SFD.FileName)
            End If
        End If

    End Sub

    Private Sub wc3_DownloadFileCompleted(sender As Object, e As System.ComponentModel.AsyncCompletedEventArgs) Handles wc3.DownloadFileCompleted
        MsgBox("Done")
        ProgressBar1.Value = 0
    End Sub

    Private Sub wc3_DownloadProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs) Handles wc3.DownloadProgressChanged
        ProgressBar1.Maximum = e.TotalBytesToReceive
        ProgressBar1.Value = e.BytesReceived
    End Sub

   
End Class