I teach computers on the side, and coming to the classroom today I noticed a Post-it on one of the computers with the error description "Does not connect to internet. John."
All the computers are connected to the same network and gateway, so I turned it on and started Internet Explorer. I quickly found the reason the computer wouldn't connect to internet: some previous pupil/teacher had set Internet Explorer to start with an empty page! Any page I tested would load with no problem at all.