Hosts文件是什么？有什么作用？ 

Hosts文件主要作用是定义IP地址和主机名的映射关系，是一个映射IP地址和主机名的规定。  

当我们的Hosts文件空白时，我们要如何修复呢？

1、在win7中，hosts文件的位置：C:\Windows\System32\drivers\etc  将它复制到地址栏>回车

2、用记事本打开hosts文件，复制以下内容

# Copyright (c) 1993-2009 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:

#

#      102.54.94.97     rhino.acme.com          

# source server

#       38.25.63.10     x.acme.com              

# x client host 

# localhost name resolution is handled within DNS itself.

# 127.0.0.1       localhost

# ::1             localhost

3、保存即可！