did I read right that you have 2 routers?
if so then for a start that is likely to cause you problems down the line.
anyhow back to the first problem,
can you ping the router from each computer. open a command prompt by clicking start then run and typing in cmd then hit enter.
then type ipconfig /all
this should give you a list of details for your network connection including your computers IP address and your default gateways ip address (the gateway is your router)
then, still in the command prompt, type ping followed by the numbers that corresponded to your gateway so it will look something like
ping 192.168.1.1
and hit enter. you should get for mesages saying reply from 192.168.1.1 if you do then the connection is working between the computer and the router. if not may well be a faulty lead or a problem with the actual network port