How do you shut off a library computer countdown?

I go to a library all the time, that isn't busy, at all to use the computer. I'm the only person that uses it but when you log in a window opens called "LIBRARY ONLINE" that starts a countdown. When teh count down ends, the computer turns off. I was wondering if anyone knows of a way to stop this? (I KNOW THIS IS AGINST THE RULES)