To keep it short and sweet as this has been covered many times here already, but I have a hidden share on our NAS server called profiles$ within this is a set of profiles for students, teachers, etc.

Within AD under the user properties -> profile I point this at the profiles share and ensure it is the students one that is loaded. Local profiles ARE NOT CREATED and as it is mandatory and read only its the same for each student.

if you want more info on profiles and the differences between them check out -->