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:

Came across a problem recently while on site with a client which I have never come across before. If you are trying to test your SharePoint Server web applications locally on a SharePoint server and you find that it is refusing to accept the locally logged on user or another user who should have access to the site by asking for your credentials 3 times before telling you that you don’t have access, it is because of a security feature within IIS which will not allow the use of integrated security for a hostheader that is not the server’s hostname.