Hello, Background: I'm a teacher working in a high school and I have a few MacBook Pros that my students use in one of my classes. All of the Macs use exactly the same settings (including Yosemite 10.10.5) to connect to wifi although one of them cannot connect to the Internet through our main account. There are a couple of WiFi networks inside the school Staff & Student - which can access most websites easily Guest WiFi - which has restricted access When I log in to the admin account it picks up the Guest WiFi even though it is not listed as the top option. I can manually switch to the Staff & Student WiFi and it doesn't have a problem logging in. However, when I go through the student account it also can identify and connect to the Guest WiFi but is totally unable to connect to the Staff & Student network (it works fine on all other MacBooks except one). The computer can 'see' the network in the drop down list but gets hung up when it tries to connect. If I go into the Admin account first, and connect to the Staff & Student WiFi and then switch to the Student account, I can then connect to the Staff & Student WiFi and it will connect and work (at least for awhile). I've tried making the Student account an Admin account but it didn't make a difference. I also tried to make a separate Admin account and the same problem occurred. I'm assuming that the issue has something to do with dynamically assigning IP addresses from the router, but I don't understand how this can work on one account but not on another?!?!?! Any help would greatly be appreciated!