Guys,
As I did not get any appropriate way to solve that, so taken shortcut to solve the problem. :-)
Below is the code to enter username and password in Windows Authentication Dialog-
InternetExplorerDriver brow = new InternetExplorerDriver();
brow.get("
http://qa.xxxx.xx.xxxx.com/sites/abc/Home.aspx");
//Code to handle Basic Browser Authentication in Selenium.
Alert aa = brow.switchTo().alert();
aa.sendKeys("username");
Robot a = new Robot();
a.keyPress(KeyEvent.VK_ENTER);
a.keyPress(KeyEvent.VK_ENTER);
Thread.sleep(5000);
Alert bb = brow.switchTo().alert();
bb.sendKeys("password");
a.keyPress(KeyEvent.VK_ENTER);
a.keyPress(KeyEvent.VK_ENTER);
First it's enter the username in first edit field then hitting the enter key which makes the system to point the second edit field. Now it will data in second edit field and hit the enter which makes the system to login through that authentication.
Regards,
Mayank