Network Problem with Strange Characteristics

I have an HP Pavilion a1130n here that I've fixed up for a disadvantaged friend that has a strange networking problem. It works fine in my shop. I took it to her house and everything about the computer works perfectly just as it does in my shop EXCEPT it will not get on the internet.

Windows says it cannot connect to the internet and offers to troubleshoot the problem; but, it always returns the message that Windows cannot repair the connection. I connected my laptop to her cable internet box and it works fine on the 'net.

I brought the computer back to my home shop and it works fine here.

Here are the facts:

• The computer I fixed up for her worked fine in my shop.
• It will not get internet access at her house.
• My laptop (Win7, MS Security Essentials) gets on the internet on same wired connection at her house.
• The computer I fixed up for her got on the 'net just fine when returned to my shop.
• There is a router at my location but no router at her location; but, I don't understand how that might make a difference.
• I installed an add-in network card while at her location; but, there was no change.

I powered down her cable modem and the computer, disconnected all wires from her cable modem, removed its battery, waited three minutes and put it all back together and waited on it to completely cycle back up before turning on her computer again; but, there was still no change.

 

Most probably the computer is not getting the IP address through DHCP.

On some modems/network cards I have seen that if you leave the card speed settings as "Auto Negotiation" the computer doesn't get a valid IP address. Try to set the computer's LAN card setting to 100 Mbs Duplex & see if it solves the problem.

 

Well, I've already got $60 and a ninety-minute drive invested in this thing for someone who cannot pay and I don't want to spend another $50 or so on a router, or even half that.

The XP system worked fine without a router and so does my laptop.

Running Windows 7 and MS Security Essentials on her computer.