Compaq Laptop CQ57 Trouble with some applications and speed.

I have 24 laptops that I use with my students. We are having some issues with programs, like Word, not responding. I was wondering if having 2 different user accounts affects anything. (we have an admin account and student account). Some computers are much slower than others and I have noticed when I go to shut down it shows some programs that need to close that we did not even need or have opened. Are there programs preloaded to automatically start that I can shut off? Any suggestions would be much appreciated.