I am assuming that you mean that they use ctr+alt+del to get to the security
dialog box and choose shutdown.
use local or group policy to manage the shutdown system right so that only
admins and tech/library staff can turn the system off.
Here is where you will get flack:
Libaray staff: I don't like the change you made to our computers!
You: why is that praytell?
Library Staff: now I have to log off and then log on before i can turn the
system off at the end of the day!
You: Sorry , I didn't mean to eat up an additional minute of your day. Would
you rather have the older problem?