Ryan Gavin, the General Manager for Internet Explorer Business and Marketing, has written in the Windows Blog that starting from January, Microsoft will automatically update older Internet Explorer versions on Windows XP, Vista and Windows 7.  This will take place for Australia and Brazil first and then, roll out to the rest of the world. Automatic Updates setting in Windows Update is required to turn on.

Ryan Gavin wrote below :

We want to make updating to the best protection possible as fast and simple as we can for Windows customers. IE is how millions of Windows customers connect to the Web, so keeping that part of Windows updated at all times is critical to keeping them safe online. With automatic updates enabled through Windows Update, customers can receive IE9 and future versions of Internet Explorer seamlessly without any “update fatigue” issues.

The Windows Blog