hi....
we begin from the problem side pc,renew your ip by repair option,or try from the command prompt ipconfig/release ,then ipconfig/renew,after this try to ping the other pc, if there is no reply check weather the cable is properly fixed on the both ends/try to interchange the cable,another thing is restart the router and the modem and try it...
and finally check your nic card is in working condition by pinging 127.0.0.1 if you get the reply then your nic card is working,try to change the cable if not working ok try this , problem will solve....
