>Thanks for responding Michel. Is ZoneAlarm a good option? I don't want to increase cost at this moment. Also will those on my LAN (W98 machines) be able to access the Internet. Actually I don't want them to at this moment.

If those are properly set up, such as gateway to your main PC, they should be able to. With the connection you have, I assume your ISP probably gave you a small range of IP addresses. As for ZoneAlarm, I don't know. Basically, I never trusted those type of software for security. For my needs, I can only rely on builtin hardware firewall such as CISCO for top security.