What steps should you take to protect these settings in the situation that you are a system administrator for a high school and responsible for five student computer labs and you need to prevent students from accessing the system BIOS on the machines?

It is beneficial to assign a BIOS password to all systems. Because BIOS passwords are conveniently circumvented by students with access to the system, you should also think about locking covers or situation alarms for lab systems. Expecting lab technicians to watch systems or installing security cameras would be prohibitively expensive, and the password would not necessarily be as secure. Obviously, removing the BIOS battery would never work.