ICMP:
https://support.microsoft.com/zh-cn/kb/832017
group policy desktop backgroup icon:
http://www.grouppolicy.biz/2011/03/best-practice-using-group-policy-to-configure-desktop-wallpaper-background/
本文出自 “苏兰网络” 博客，请务必保留此出处http://zhangfang526.blog.51cto.com/8588740/1716914
group policy troubleshooting
原文：http://zhangfang526.blog.51cto.com/8588740/1716914
