# 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:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
127.0.0.1 localhost
0.0.0.0 3721.net
0.0.0.0 www.3721.net
0.0.0.0 cnsmin.3721.net
0.0.0.0 down.3721.net
0.0.0.0 download.3721.net
0.0.0.0 activex.3721.net
0.0.0.0 3721.com
0.0.0.0 www.3721.com
0.0.0.0 cnsmin.3721.com
0.0.0.0 down.3721.com
0.0.0.0 download.3721.com
0.0.0.0 activex.3721.com
0.0.0.0 bar.baidu.com
0.0.0.0 cns.3721.com
0.0.0.0 page.taobao.com
0.0.0.0 www.taobao.com
0.0.0.0 taobao.com
0.0.0.0 www.unionsky.cn
0.0.0.0 unionsky.cn
0.0.0.0 ddd.dudu.com
0.0.0.0 diy.51.net
------------------
文件名hosts，路径c:/windows/system32/drivers/etc/ 或者 c:/winnt/system32/drivers/etc/
不断添加新的。