I am helping a friend with her new Dimension PC.  The Internet connection keeps going out and then will come back.  Sometimes I can surf the Internet fine and sometimes I receive no connection, little popup window will come up with "network cable is unplugged".  I cannot figure out if we are having problems with the NIC or the DLINK router we are connected to.  I ran a IPCONFIG.  IP address was 192.168.0.101.  I run a continuous ping and it will reply for awhile then stop replying, request timed out, a couple of times then hardware error.  I then immediatly run ipconfig again and my IP is now 169.something.something.something. Which tells me I lost connection, but why?  Do you think it could be the NIC or the DLINK router?