Need app. to set secure file permissions on WinNT4 (e.g. for C:\WINNT\*)

Hi,
I had to reinstall NT4 SP6a on about 20 boxes which are supposed to be
used in a school's classrooms. Obviously, this is a very hostile
environment for the computers ;)
My problem is: The default NT4 file permissions of course don't give any
security since, for example, everyone has full write access to
'C:\WINNT'.
It would be perfect if it was like in e.g. WinXP, where there can be a
group of power users (=> teachers) which can install software but still
have limited permissions and a group of normal users (=> students) which
cannot modify the system at all.
For sure, I could set those permissions manually - but that would take
very much time with 20 computers and it might still not be perfect
because the WINNT directory has many subfolders which could need
specialized permissions (fonts directory, print spooler directory,
etc.).

So my question is: Is there any software which can set those file
permissions _automatically_ - at best officially from Microsoft?

Otherwise I would have to program that myself which will also take much
time - I'd like to get the computers done this week.

Thanks for your help!