Windows 2000/2003 Security

I am looking at a way to restrict users to be able to login from any one machine on network. They have flexibility to come every day and login to any of the machines available on network..They should be able to login from two machines ...

Hi all, I wonder whethere there are some ways to delegate specific rights to some ones who are able to logon server locally, start and stop certain services, kill certain processes, reboot/shutdown servers? Thanks in advance. Pakeon ...