Win98 SE Firewall?

[Peter Vincent <vincents1701 () home com>]

I just got a copy of the memo: Help, someone hacked into my home
computer!

It identifies a problem but offers no solutions. From your e-mail
address I assume you have a solution or two to suggest. Given a home
Microsoft LAN with 4 PCs connected to a hub (via RJ45 cables) and one
system dedicated to being the communications server (P120). This server
has a second PCS ethernet card for the cable modem. What freeware or
shareware firewall can you recommend to keep snoopers out?

Many thanks for any advice,

Peter Vincent