At home we have three computers networked. LAN on XP. All computers run XP (unfortunately...I am an old luddite who prefers '98, but for some reason I can't easily configure my rather strange monitor on '98...but so be it). Net access is through a cable modem on one of the machines. All machines show the same IP to the internet. We use zone alarm on all three machines, but tests (mucking about with http://grc.com , that is) and common sense suggest that we only actually need it on the one machine that the cable modem is plugged into. Can experts please confirm this before I uninstall the surplus copies? Many thanks.