Create a separate form in your application for server settings which will update your app.config file.
Use these are at top in your form coding. Change the name of "MMISCONFIG" to your connection string key.
Imports System.IO
Imports System.Text
Imports System.Configuration
Imports Microsoft.Win32
Imports System
Private Sub btn_save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_save.Click
Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)
If Me.rb_ipaddress.Checked = True Then
config.AppSettings.Settings.Item("MMISCONFIG").Value = Me.txt_ipaddress.Text
Else
config.AppSettings.Settings.Item("MMISCONFIG").Value = Me.txt_server_name.Text
End If
config.Save(ConfigurationSaveMode.Modified)
MsgBox("The Server Name/IP Address successfully Changed." & vbCrLf & "For New Settings your application will restart automatically!", MsgBoxStyle.Information, "Server Alert")
Application.Restart()
End Sub</pre>