msn突然登錄不了，且重新安裝都無法解決的情況下，可以修改windows的hosts文件來解決。
文件路徑：
C:\WINDOWS\system32\drivers\etc\hosts
文件內容：
# Copyright (c) 1993-1999 Microsoft Corp.
## This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
127.0.0.1 localhost
65.54.239.80 messenger.hotmail.com
65.54.239.80 dp.msnmessenger.akadns.net