can't connect since moved pc home

This has got me stumped. I had an old pc aptiva pentium II 400 mhz, 320 mb. I upgraded it to xp pro, reset the bios to default, everything worked fine, surfed the net through ethernet charter cable. I sold it to a girl, she took it home and cannot connect to charter cable at her place. The tech came out and still couldn't do it. He uninstalled the adapter, rebooted, reset the modem, pinged the modem, its fine, her other win98 pc connects fine to it. what the?? Any ideas? I'm thinking I may go over and uninstall the adapter in safe mode, I don't get it, it connected here no prob!! I downloaded a program called winsock, could that do it? Any help appreciated!confused

 

I forgot to mention, I disabled plug & play in my bios too before moving it, if that makes any difference.