LAN usage with 4Port wireless Broadnad Modem

Hello,
i have 4 port with wireless modem for my broadband connection.
The modem is provided with 4 RJ45 Ports and also with one USB Port + Wireless Antena.
I have 3 systems. 2 systems are fixed with NIC Cards. and the third one is with Wireless Card.

I have connected the modem with UTP cable. I have connected the 2 systems. Now all systems are working very well with broadband. The third system is also working very well with broadband through wireless.

Now the problem is i am unable to use LAN between these 3 systems.

I am unable to acess the systems through LAN.

I want to use LAN also. Please help me.