[Blind-sysadmins] network question?

hello members: I've small home network in my home, using it to get DSL connection. we have Conexant router. this is its info: BootCode Version: BC_CX82xxx_4.1.0.21 Firmware Version: CX82xxx_4.1.0.21_S Customer Software Version: 4.1.0.21_ please I've some questions: 1. how can I know the computers that are online now on network? net view command now not working. also when I go to Entire Network, then press Microsoft windows network the computer not talk, and should use end now to be healthy again. why this option not working now? and how I fix this? 2. is there any way make me prevent any virus or spy move from the network to me? am not share any files or folder for anyone. thanks. ibraam.