Win2K Problems Please HELP!!!!

First, I work for the department of juvenile justice in South Carolina. I have teacher that leave there workstations up and student get in a change the admin password. Is there any why to get pass the administrator login and/or change the password?
Second, I have two Win2K workstations that are stuck in a loop and keep rebooting during boot up. I also have some information on them that is needed. Can anyone tell me how to fix this problem so I won’t lose everything or can someone tell me howto get the information off?

Thanks in advance.
Russell Harris