Nginx + php 配置 用IP的方式能访问 域名的方式却不可以

我Nginx 使用localhost:81或者127.0.0.1:81 可以访问 可用设置的域名访问不到这是为什么？
这是nginx.conf 的代码：

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       81;
        server_name www.test.com;
        root D:/src/web/runroot;
        error_page 404  /404.html;
        error_page   500 502 503 504  /50x.html; if ($remote_addr !~ "123.125.169.174") {
        #       rewrite ^ http://lavaradio.wix.com/lavaradio redirect;
        }
        rewrite ^/api/(.*?)\.json$    /index.php?route=api/$1&_of=json break;
        if (!-f $request_filename) {
            rewrite ^/(.*?)$    /index.php?route=$1 last;
        }       
        location /index.php {
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }
    }    
}

我的C:\Windows\System32\drivers\etc\hosts文件：

# 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 www.test.com

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你hosts中是 127.0.0.1 www.test.com
访问域名就到了 127.0.0.1:80 端口了，默认是80
但是你的服务器端口开的是81

---

访问 www.test.com:81