Assistance with locking user rights down

I have recently set up some new Windows 2000 workstations in a lab environment where they have a few trouble makers and they are wanting the rights of the default user ID that I created locked down. I have done this before in the past but forgot what keys in the registry to modify. I found some things online but the keys that they mentioned do not exist. Any assistance with this would be greatly appreciated. I want to stop access to the control panel and changing the dekstop settings, as well as installing programs.