Question:
When I do a property box on a file/directory, the Security sheet changes from the normal (NT4, SP0) one to a new one. Can you explain this?

(I have installed NT4, SP5 recently, although other NT4 Server boxes don’t do this.)

Answer:
This is the new look, so you might as well enjoy it.

You could actually install with this SP4 by installing an add-on component called the Security Configuration Editor (in the MSSCE subdirectory).

I’m guessing that installing it is the default for SP5 (all my machines already had the new security editor installed via SP4). It is a much-improved security editor.