It is very simple to lock a device down to one or more classrooms regardless of who logons to the device. 

1. Click on the Admin Center (Cog Top Right-hand corner)
   
2. Select Devices from the left-hand menu
3. Select the device you wish to restrict to the room
   
4. Click the blue Edit button from the Devices menu bar
   
   
   
5. Select the Restrict Groups Tab and select one or more groups that you wish to restrict this device to
   
   
   
6. When any user logs on to this device they will only see the Restricted Groups
   
   

*See also Restrict Group Access