How to block a domain user in logging to unnecessary computers?

Hi Experts,

One of my client who is an computer institute, having an issue with the domain user "student".
The student user is a common domain account given to all the students.
The students with common domain id logging in to the teachers computers and this creates various issues;

I tried adding the computers netbios names in the "logon to" in the students OU, but since the computer names are not uniquely named in order, and also number of computers also high. I require a better solution.

Please advise.

Umesh