Put simply, we are updating our approach to DNT to eliminate any misunderstanding about whether our chosen implementation will comply with the W3C standard. Without this change, websites that receive a DNT signal from the new browsers could argue that it doesn’t reflect the users’ preference, and therefore, choose not to honor it.
As a result, DNT will not be the default state in Windows Express Settings moving forward, but we will provide customers with clear information on how to turn this feature on in the browser settings should they wish to do so. This change will apply when customers set up a new PC for the first time, as well as when they upgrade from a previous version of Windows or Internet Explorer.
More information - http://blogs.microso...o-do-not-track/