3 computers on same router- 2 networks- how to get on same network?

Somehow my computers have come up with 2 different network names for what appears to be a single network. I can't find a way to make all computers "see" the network the same.

I have my desktop ("A") running Win 7, wired connection to "network 2", my laptop ("B") running win 7, wireless connection to "my home network" and my son's laptop, running Vista ("C"), wired connection to "my home network".

"A" will only recognize "network 2" and the other 2 will only recognize "my home network".

A will see only C and says it's on "network 2." A does not see "my home network."
B will see A and C on "my home network." B does not see "network 2."
C will see only A and says it's on "my home network." C does not see "network 2."

I attached a diagram illustrating the problem. Any ideas how to sort out this mess?

Allen

Are they all using the same workgroup name, and is the router set to allow home networking, the network names are set on the machines, so the identification of "network 2" can easily be renamed, it it likely this machine has previously been on another home network.

For the router setrtings it's best to check your manual as different manufacturers call it different things. But the wireless and wired networks are kept seperate and sometimes machines on the same network arent able to comunicate either, on mine the setting is called: virtual server.

Can you ping each machine from each other machine? Firewalls can often be an interfering factor, as a tempory measure you might try disabling firewalls untill you have it working and then enable each one and give them the right permission setting on an individual basis.