In theory, that's what the firewall is already doing
I suspect that what you mean is that you want to prevent that computer accessing the internet?
If so, then that's a whole different ballgame.
The best solution is to prevent ALL access to that computer except for authorised personnel - who may need internet access for updates etc. - and limit them to user accounts rather than admin accounts (except for the real admin) - you can then lock down User account access using GPO if you have Pro or Ultimate (but I have to admit that I don't know the specifics)