I don't know what it is, but after he left, I hooked up my router, and 7 other PCs with no software installed, and it worked on all of them, so I know you don;t need it. It has been a while, but I think I had to enter some info into the router to make AT&T think it was a PC, like the computer name or something. Just check all of the setups before you put your router in place (I assume you will be using one, it is best to have a firewall)