Vb.net problems download - vb.net

Question

How can I do a check that first download something and only after that it starts up the program.exe?
I already tried to do something like this but it excutes the file when the download is not finished and it throws some errors.
my Code:
Dim client As WebClient = New WebClient
Dim SourcePath As String = "C:\ProgramData\KDetector\UserAssistView.exe"
Dim SaveDirectory As String = "C:\ProgramData\KDetector"
Dim FileName As String = System.IO.Path.GetFileName(SourcePath)
Dim SavePath As String = System.IO.Path.Combine(SaveDirectory, FileName)
If System.IO.File.Exists(SavePath) Then
Process.Start("C:\ProgramData\KDetector\UserAssistView.exe")
Else
client.DownloadFileAsync(New Uri("http://ge.tt/70n8YPr2"), "C:\ProgramData\KDetector\")
Process.Start("C:\ProgramData\KDetector\UserAssistView.exe")
End If

Answer 1

You are calling the asynchronous DownloadFile method. Asynchronous method will not block the calling thread.
In order to avoid the problem, your code must be like this:
Dim downloadLink As String = "http://www.nirsoft.net/utils/userassistview.zip"
Dim saveFilePath As String = "C:\ProgramData\KDetector\userassistvkew.zip"
Dim fileName As String = Path.GetFileNameWithoutExtension(saveFilePath)
Dim client As WebClient = New WebClient
Try
CheckExsist(saveFilePath, fileName)
'Before was client.DownloadFileAsync(New Uri("http://ge.tt/70n8YPr2"))
client.DownloadFile(downloadLink, saveFilePath)
MsgBox("Download file completed. File saved in: " & saveFilePath)
'Zip extraction stuff
Catch ex As Exception
MsgBox(ex.Message)
End Try
This is the CheckExsist sub:
Private Sub CheckExsist(ByRef sourcePath As String, ByVal fileName As String, Optional ByVal counter As Integer = 1)
If System.IO.File.Exists(sourcePath) Then
sourcePath = sourcePath.Replace(Path.GetFileName(sourcePath), "") & fileName & "(" & counter & ")" & Path.GetExtension(sourcePath)
counter += 1
CheckExsist(sourcePath, fileName, counter)
End If
End Sub
I manage to download the software (from the official website) and save it as a .zip. Code the last few rows to programmatically extract the .zip, if you ecounter any problem or bug feel free to ask with another question. Anyways there are alot of post on SO regarding zip extraction on vb.net