IOptions Window Property WebDriver
Gets an object allowing the user to manipulate the currently-focused browser window.

Namespace: OpenQA.Selenium
Assembly: WebDriver (in WebDriver.dll) Version: 2.35.0.0 (2.35.0.0)
Syntax

IWindow Window { get; }
Remarks

"Currently-focused" is defined as the browser window having the window handle returned when IWebDriver.CurrentWindowHandle is called.
See Also