Users and passwords policy

I own a Win2000Server Server and a 300 comp domain. I had the surprise of not beeing able to enter the C$ or D$ partitions on several wise guys machines because they removed the remote services.

My questions are:
1. How can I implement a domain policy to restrict user`s access to Users and Passwords from Control Panel as I cannot find the corresponding cpl file for that item.
Is it enough to restrict access to lusrmgr.msc ?
2. How can I prohibit access to sevices as I`m obliged to allow most of them to have local administrator rights.

Thank You in advance and hope someone reply,
Lucian ANASTASIU