https://blog.csdn.net/u012509485/article/details/78459584
在WIN7下解决coursera视频无法播放问题
2019/1/20 23:18
最近Cousera一直表现不佳，课程视频无法观看。小编结合网上找到的信息，操作一番便解决了问题，视频也可以正常观看了。特别感谢百度用户@wintel886
工具/原料：win7 64位系统，记事本
方法/步骤：
1、首先是win+s找到记事本，并用管理员身份打开，
在记事本 页面使用ctrl+o打开hosts文件，路径是C:\Windows\System32\drivers\etc，右下角的选项改为“所有文件”，不然是找不到hosts文件的，
# 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
2、阅读上面的添加规则，然后如图所示输入如下内容：
# 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
52.84.246.90 d3c33hcgiwev3.cloudfront.net
52.84.246.252 d3c33hcgiwev3.cloudfront.net
52.84.246.144 d3c33hcgiwev3.cloudfront.net
52.84.246.72 d3c33hcgiwev3.cloudfront.net
52.84.246.106 d3c33hcgiwev3.cloudfront.net
52.84.246.135 d3c33hcgiwev3.cloudfront.net
52.84.246.114 d3c33hcgiwev3.cloudfront.net
52.84.246.90 d3c33hcgiwev3.cloudfront.net
52.84.246.227 d3c33hcgiwev3.cloudfront.net
请严重注意：IP地址和域名一一对应。必须换行的。我这里就出现了看完一个视频之后，第二集看不了啦！想想可能是IP地址改变了！
https://www.coursera.org/learn/os-virtsecurity/lecture/uLyXm/1-1-ke-cheng-jian-jie
https://www.coursera.org/learn/os-virtsecurity/lecture/6zH6o/1-2-ji-suan-ji-xi-tong-de-an-quan-xing
再次感谢大神百度用户@wintel886提供的IP
3、win+R打开cmd,输入ipconfig/flushdns刷新一下dns。
Microsoft Windows [版本 6.1.7600]
版权所有 (c) 2009 Microsoft Corporation。保留所有权利。
C:\Users\Administrator>ipconfig/flushdns
Windows IP 配置
已成功刷新 DNS 解析缓存。
C:\Users\Administrator>
再打开coursera,然后课程就可以看了。好好学习，天天向上&&