block installation of programs in 98/95

[Riddler]

i've searched quite a bit on the net and couldn't find the right program- i'm a computer lab manager for a public library, most of our workstations are windows 95 or 98. i'm wanting to stop people from installing programs on the workstation. i have security software that saves the setting on the computer so that when you reboot all changes are erased, and the computer is reverted back to it's original state, but it still doesn't stop people from installing crap, then leaving, and all the crap is still there for the next person.

any help would be greatly appreciated!!

thanks