When I try signing in to hotmail a Windows Live screen sometimes automatically comes up asking me to add more security details, ie. mobile number, trusted pc, alternative email add, security question.  Is this genuine and, if so, is it just a case of answering one of these rather than all?  I would never respond to an actual email asking for info like this but can only presume as it's an actual page that pops up after signing in that it IS genuine....but you get so wary about anything these days!!