Do Not Track is enabled by default in Internet Explorer 10. This setting asks websites not to track the user's browsing behavior for the purpose of serving targeted ads, but it's still up to those sites to actually comply with the request. Microsoft's decision to enable Do Not Track has caused a controversy, since advertisers believe users should have to opt out of tracking. As a result, some companies have said they'll ignore Internet Explorer 10's Do Not Track settings .
To download the preview of Internet Explorer 9, head to Microsoft's website.