This one annoyed me for longer than I wish to share… If you are having problems using Windows Authentication on IIS (in particular with the ADFS 2.0 passive federation) where you can login fine with Internet Explorer but Google Chrome simply repeats asking for your login and password then this is for you! IIS has a new feature called “Extended Protection” for Windows Authentication. The appears to have an affect on Chrome but not IE, therefore to disable it do the following: