I've got a Microsoft Infastructure class this semester and need some help with security. We have established a domain of about 25 computers with a variaty of OS(XP pro,2000 pro,NT workstation,NT 4.0,2000 server,2000 advanced and a fedora server and a couple of Fedora workstations) Each person in the class has a diffrent OS and we have learned how to get them to all work together. But now that we have most of the bugs worked out the instructer has a new twist, One member of my class we have no idea who, has been instructed to hack us at will and do as much damage as he can. I am running a 2000 advanced server as a Domain controller with WINS and DNS on it. Last week he pretty much had his way with a couple of peoples machines and I don't want to be next, can anyone give me any ideas? Please remember I'm still new at this. I'm smart enough to know that I know nothing.