(See the ACL2s home page/documentation for general information)
The computer labs here have Eclipse with ACL2s installed. It should be located in the start menu under Department Applications | CCIS Applications | Development Tools | Eclipse | eclipse. Running Eclipse for the first time, you will be prompted for a workspace location. We recommend "Z:\Workspace", because this is in your personal drive that is backed up by the college. You must have logged in with your CCIS account for that to location to work.
That should be all that is special about running Eclipse in the labs, but if the session still won't start, it might help to change one setting: In Eclipse, go to Window | Preferences.... On the left side, expand the ACL2s category and select the ACL2 preference page. Under "ACL2 bulid path" type "N:\arch-windows\acl2-3.4", like so: