OK, this is quite unusual to see a wireless LAN works separately from its wired LAN network using an All-in-one hardware without being able to route between the networks.
Try to factory-reset the hardware and just enter the basic setup one at a time:
1) set your internet WAN setup
2) set your LAN setup or use its default setting (the router's IP addres must be the default gateway IP address let say 192.168.1.1 for all machines that are connected to it in the same subnet let say 192.168.1.x and within its allowed subnet IP range let say let say 192.168.1.2-192.168.1.254. The router hardware usually has a DHCP server running. If a network happens to have more than one DHCP server running on the same subnet, one of them must be disabled to avoid IP conflict; otherwise each DHCP server shall using a different subnet and must be routed accordingly to be able to see each other.)
3) set your wireless setup
4) Try to ping each other (disable Windows 7 firewall on each machine's setting first before pinging)
This post has been edited by eclectice: Oct 23 2012, 10:16 AM
Wireless Problems TPLINK TD-W8951ND, Wireless LAN workgroup problem