Locked - Switch users

In 2003 when I wanted to walk away from a server I would CTRL-ALT-DELETE and lock the machine. With 2008 I noticed that when I did that there was an option to switch users. And I was able to log in as another user while my Administrator account was locked.

Has anyone found a way around this so that when its locked only that person may unlock?

Haven't got a 2008 server to try this on, but these instructions apply for vista, so guess they should do what you want:

Start,Run --> Gpedit.msc --> Local Computer Policy, Computer Configuration, Administrative Templates, System, Logon --> “Hide entry points for Fast User Switching

Steve