I have two computers connected to the same router - connected through LAN ports 1 & 2. I just want to be able to play LAN games but apparently our computers can't detect each other.
There is nothing in your networking setup that would prevent your computers from detecting the other. I have not seen a router that has client isolation for wired ports. It has to be something on the PCs. Firewall would be the obvious thing.
Start by opening a cmd.exe window and running ipconfig /all on both computers. Verify that they have similar IP addresses (192.168.x.y) The only thing that should be different is the last number in the IP address.
Once you have the IP address of both machines verify that you can ping them. In the...