not found frame for calculator

[SaveliyShur]

Hello, i am begginer qa, and i wrote small application for calculator, but my code don't found my "frame"

        var dc = new DesiredCapabilities();
        dc.SetCapability("app", @"C:/windows/system32/calc.exe");
        var driver = new RemoteWebDriver(new Uri("http://localhost:9999"), dc);

        var window = driver.FindElementByClassName("CalcFrame");
        window.Click();
        var resultField = window.FindElement(By.Id("150"));
        resultField.GetAttribute("Name");

        driver.Quit();