This was asked just the other day, see
here...
Please search first before making threads.
And this goes also for the helpers, if the question is already asked refer to that thread instead of starting everything over again (with the chance to give incomplete information -as it happened again in this thread-).
-----------------------------
MSN login emails are .NET Passports, these are saved as credentials. To manage your credentials see (as so many times asked before -hint: search forums-):
CookieRevised's reply to 'Deleting credentials in Windows XP'