I have a situation where I want to take away the ability of our helpdesk staff (need it for some admins) to uncheck this option when they change a password. Some staff have been setting the password back to the old one and then unchecking the box. I know this is a trainig issue but if we could eliminate their ability to uncheck the box the issue would be solved.
In my limited experience as a sysadmin, let me ask, do you have that as part of a Group Policy? If it is part, of a Group Policy, wouldn't that override the help desk staff?
Here is an article on how to fix the situation you are trying to implement if I understand your question correclty...you should be able to figure it out from here...