Problem with Greek characters while streaming data from url

[georgizas]

I try to get a file from a url and save it to my pc but I have problem with Greek characters. My code is:
Public Function OpenURL(ByVal strURL As String) As String
Dim client As New System.Net.WebClient()
Dim data As System.IO.Stream = client.OpenRead(strURL)
Dim reader As New System.IO.StreamReader(data)
Dim s As String = reader.ReadToEnd()
data.Close()
reader.Close()
Return s
End Function