new InternetExplorerDriver();
But I could see exception as below:
OpenQA.Selenium.DriverServiceNotFoundException was unhandled by u
Add these lines to your code before creating the object.
System.setProperty("webdriver.ie.driver",
"E:\\path where your IEDriverServer is located\\IEDriverServer.exe");
You can download IEDriverServer.exe file from here.
As you are using C# you can use the below code.
private const string IE_DRIVER_PATH = @"C:\PathTo\IEDriverServer";
var driver = new InternetExplorerDriver(IE_DRIVER_PATH, options);