System.Configuration.ExeConfigurationFileMap map = new System.Configuration.ExeConfigurationFileMap();map.ExeConfigFilename = "C:\\SomeOtherApp\\web.config";System.Configuration.Configuration config = System.Configuration.ConfigurationManager.OpenMappedExeConfiguration(map, System.Configuration.ConfigurationUserLevel.None);string name = config.AppSettings.Settings["KeyInOtherApp"].Value;