Well, in this case, Flash Player. I'm not sure exactly how you'd do it, but as with most applications, there's probably a way to enable it for all users.
You may want to look and see where the add-in is located in your administrative account. If there is a similar location that is not under a user profile, you can put it there and it will become a setting for all the profiles. I am thinking of something akin to making shortcuts available on all desktops, rather than just for the profile you are working with.
If I get more time later, I'll try to take a look and see if I can find how that would work so I can give you detailed instructions. In the meantime, you can look around and see if you can find it.