internet not working

i m workimg in a network of around 72 nodes but among them internet is runing only on 10 nodes one of them is proxy server now if i configure the same gateway address(proxy server address) and tcp port no 8080 to other computer where internet is not running still internet does not start on that, here plz note that i m configuring that computer in the same way like the othes where internet is working,

means: 1. giving the gate way as proxy servers ip
2. applying the por no 8080.
3.that computer is pinging with the proxy and with the othe where internet is running
plz help