I have a question that maybe somebody has already figured out.  I want to block VPN based access to systems like Hamachi.  I know in parental controls I can block the EXEs for the control portion of it but not the Device Driver. 
In BitDefender for example there'll be a Hamachi network.
Any other ideas with the Firewall or Parental controls to prevent this.  Yes, I can log on and remove it once but these are kids we're talking about... LOL