Preventing tor installation on Win8.1Pro

Hi,

I am trying to control some user computers from accessing pornographic material. So far, I have managed to block a lot with OpenDNS. However, there is a flaw in the system. Once tor has been installed, it can bypass OpenDNS.

I am trying to secure a normal account. I have already changed the default access of the account to tell me if the software is being installed. It works with a lot of software, however it does not work with tor, I have no idea why that is. I have also removed the admin profile rights of the account to just normal user.

How do I prevent tor being installed? I don't mind a 3rd party software that specifically filters for tor. I noticed that the UAC popup box does not come out for Tor. If I can block tor from installing the first place, then I can block the "tunnel" out of the system.

Maybe I can do one of these? http://www.thewindowsclub.com/how-to-prevent-users-from-installing-programs-in-windows-7

Or this? http://www.thewindowsclub.com/program-blocker-free-download

Or this? http://www.howtogeek.com/howto/6317/block-users-from-using-certain-applications-with-applocker/

Is there a way to force all net connected software for using only the OpenDNS IP?

Thanks