If you don't have it yet, you're going to want to buy DeepFreeze from Faronics. You set up you equipment how you want it to be and then install this software which prevents any permanent changes from taking place on the computer. Kid delete stuff or otherwise screw up the laptop, just reboot and you're back in business!
In your case after installing this on the laptops, you'd tell your teachers to simply restart the laptop to correct this issue. Otherwise, I know on our Dell laptops you can turn off the wireless button in the bios making the wireless control software only.
Good Luck!