Microsoft ISA 2006/TMG 2010 is Microsoft's firewall/proxy/vpn software. So unless you're using this server as your gateway to the internet, I would advise against it. ISA/TMG isn't all that easy to configure out of the box akin to a Linksys router or the like. I trust you have a Technet subscription? If you do, I'd run Hyper-V or VMWare ESXi on a test box and play around with the software some. At the very least, configure the default Windows Firewall on the system. Hope this helps.