Network Problem

Can someone please help, I have run out of ideas:

I am setting up a home network. I have an ADSL Modem/Router with Broadband connection. 1 Desktop PC running Windows XP Home, 1 Desktop PC running Windows 98SE and 1 Laptop, also running Windows 98SE. All are connected to the router via Cat5 ethernet cable and all can connect to the Internet.
The problem is when I try to set up the LAN, none of the computers can see each other. They are all the same workgroup, the xp says the LAN is connected at 100Mbps, they all have the same User names setup.

Thanks

did you run the Network Setup Wizard?

noted here:

Network Setup Wizard

that post from a broader search here:

computers cant see each other

Thanks for your reply.

I have followed the instructions in the link you provided, but it still doesn't work.

I am sure it is something simple, but I can't see it.