First) If your config file is beside your exe file and it is read only and won't change then you can use:
protected string file = Path.GetDirectoryName(Application.ExecutablePath) + "\\configSetting.ini";
Second) If your config file changes then you should save in the users data folder instead (since "Program Files" is protected by Windows and requires admin permissions for writing to):
Where should I store my data?[
^]