Network Connection Error at Home cable " No Cable Connected " Works in work location on T1 connection

I have a Dell Inspirion 1000 Model PP08S and had to reload all the original software. The machine will not connect via my Comcast Netwrok at home however the machine works fime in work location running on a T1 line. My home cable is fime and I run 2 other IBM laptops with no issues. I have gone through all of the network settings on the Dell while at home and it still comes up with cable issue on a good cable connection line. I understand that there may be some type of network speed setting for the network on this Dell however I must be having a DUE on my part. I would appreciate any suggestions as this is a friends machine that I have been trying to assist with and they are fatiqued with the machine.