It's easier to reset them than to lock them down, and you do want your older
students to learn to customize Word. There are several approaches you could
take.

1. If you are the person who shuts the computers down, the simplest thing
would be to make sure the "Prompt to save Normal.dot" option is enabled,
then say no when asked if you want to save it.

2. You can set Word to start using the /a switch, which will suppress
Normal.dot, the Registry, and any add-ins, which means you would always
start with a plain-vanilla, factory-default version of Word. The downside to
this is that it would prevent you from saving any changes in settings that
you might want to make (and there are some defaults that you *would* want to
override.

3. You could rename/regenerate Normal.dot at startup, but that would have
many of the same drawbacks as #2 (except that you would preserve settings
that are stored in the Registry, including Options settings).

4. You could save a copy of Normal.dot set up just the way you want it in
another folder and use it to replace the current copy at startup.