.NET [VB.net]Application patcher using dropbox

Code
Imports System.Net

Imports System.IO

Imports System.IO.Compression



Public Class Form1



    'Dims

    Dim masterpath As String = "where is the installed program"

    Dim versioncheck As String = "yoursite .com/version.txt"

    Dim link As String = "direct link for zip file"

    Dim zipPath As String = masterpath & "downloads\update.zip"

    Dim extractPath As String = masterpath & "files"

    Dim checkerplace As String = masterpath & "downloads\checker.dat"

    '#########################################

    '#                                       #

    '#          Application Patcher          #

    '#          Made by titanbullet          #

    '#            Version 1.0.0.0            #

    '#         Don't forget to update        #

    '#           the app.manifest            #

    '#                                       #

    '#########################################



    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        'Gets if its the first time running the patcher. If it is,it opens "Installer" form.

        If IO.File.Exists(checkerplace) Then My.Settings.Installed = True

        If My.Settings.Installed = True Then

            'Gets and sets the current application number

            Dim currentversion As String

            currentversion = Application.ProductVersion

            oldversion.Text = currentversion

            'Gets version.txt from server and sets it on label

            Dim request = DirectCast(WebRequest.Create(versioncheck), HttpWebRequest)

            Dim response = DirectCast(request.GetResponse(), HttpWebResponse)

            Using sr As New StreamReader(response.GetResponseStream())

                Dim versionnew As String

                versionnew = sr.ReadLine

                NewVersion.Text = versionnew

            End Using

            'Compares the versions and informs the user if needed

            If oldversion.Text = NewVersion.Text Then

                'Insert your form connection here (mainform.Show-Me.close)

            ElseIf oldversion.Text < NewVersion.Text Then

                MsgBox("New update found!", MsgBoxStyle.Critical, "Update found!")

                'Deletes old files

                IO.Directory.Delete(extractPath, True)

                'Creates the directory again

                IO.Directory.CreateDirectory(extractPath)

                'Downloads the update package

                My.Computer.Network.DownloadFile(link, masterpath & "downloads\update.zip")

                'Extracts

                ZipFile.ExtractToDirectory(zipPath, extractPath)

                'Deletes the update zip

                IO.File.Delete(masterpath & "downloads\update.zip")

            End If

        ElseIf My.Settings.Installed = False Then

            'installer.show

        End If

    End Sub

End Class