Networking problems with my Inspiron E-1505

I have had nothing but trouble connecting to the Internet, and Dell tells me it must be my router, but I talked with Belkin, and everything checks out with the settings, etc. I can't connect with a hard cable or wireless. Does anyone have any ideas? Dell says the networking adapter must be bad, and you guessed it, right after the warranty expired. The problem originated right before the warranty expired but I was moving and never had time to fully delve into the problem. Can anyone assist? Thanks, and have a good day...