I am using Norton Internet Security in the old office I have got no problem with shared files between 3 computers, and shared printers (USB printer not network printer), and pinging

I moved those 3 computers (XP SP3) from the old office to a new office, and I changed the router from Netcom (10.0.0.1) to Linksys WAG54G2. ip addresses for computers changed from 10.0.0.x to subnet 192.168.1.x

Now all 3 computers are able to ping 192.168.1.1 (Linksys router ip address)

But those computers cannot ping each other

When I disabled 2009 Norton firewall (temporarily for 15 minute ), they were able to ping each other .

How can I fix this issue?

Thanks