System.Reflection.Assembly.GetExecutingAssembly().Location

String path = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

string myPath = Application.ExecutablePath;

var binariesPath = string.IsNullOrEmpty(AppDomain.CurrentDomain.RelativeSearchPath)
                    ? AppDomain.CurrentDomain.BaseDirectory // Windows Service
                    : AppDomain.CurrentDomain.RelativeSearchPath; // Asp.net