Thanks for getting to me so fast.
The router is a Linksys.
Computer is HP Compaq d530 SFF
s/n USU40404WT
p/n DS170US#ABA

I always ran fine with just the cord from my cable modem to the PC and then the blue ethernet cord to the Linksys.
After windows install i had to run a USB from cable modem to PC so Pc WOULD RECOGNIZE IT AND I COULD LOAD DRIVERS. nOW pc WILL NOT HAVE INTERNET IF i DISCONNECT usb FROM CABLE MODEM TO pc. (SOORY i WASNT LOOKING AS I TYPED)