Demilitarized Zone .. that is DMZWell.. Once you do DMZ, your computer can be accessed from anywhere using softwares... It is more vulnerable to Trojans and other viruses. If you have a good firewall, then you can use DMZ. In one word, all the ports are forwarded to this particular PC ! So, if ports are open, there is a chance of vulnerability ! I do that only when i have lots of services running in that computer Like webpage , torrent, ftp server, some online radio stuff... if you just need one or two applications, you neednot open all the ports blindly !!I say, if you have a firewall, then you can DMZ (if no other solution exists)