older computer-2009.  Have Vista operating system.  Receive emails through 3rd party (Charter).  On Charter site I can receive and send emails.  On Windows mail (not Live Mail), I can only send, cannot receive messages.  I receive a window "Logon to mail.charter.net. Please verify that both username and password are correct for your mail server."  I am unable to find this information to get past Windows Security.  I'm stumped as to how to fix this problem.