The popularity of the Internet has made it very easy for schoolchild to use the Internet, but it is also simply to surf the Internet and cause addiction to online games and online video watching. Schoolchild access the internet by using computers or mobile devices, and report show the proportion of internet access through mobile devices has gradually increased in recent years. Therefore, the paper primary main subject is a reliability defensive architecture which including protection mechanisms for conservation computer versions and mobile devices. As Network Guardian Angels (NGA) been developed in window version that has been 81,038 user downloaded since the development is completed. And also the mobile version protection mechanism has been downloaded and used. The tools of this article have also been recognized by the ministry of education in Taiwan, and have been promoted to download and use by parents of all school-age children. The developed tool has more than 100,000 downloaders since 2007.