Limited or no connectivity

Customer has a small XP network that's been running fine.  This morning their cable router stopped working, so they cycled the power, and everyone is now running fine except for one computer.  It is getting the limited or no connectivity error.  I have tried a couple of things that have not helped:

1) They have always gotten DHCP addresses, but for this problem computer, I tried having her hard code an IP address, subnet mask, gateway server, and the two dns addresses, all based on what I saw on the ipconfig /all info on one of the other computers that's working fine.  Of course, I used a slightly different IP address.  

2) I had her plug her network cables into a different port on the switch that they are all connected to.  She still could not get on the internet, so I had her reset her TCP/IP properties back to 'automatic'--and she then go the same limited or no connectivity error.

What else can I try to solve this problem?  I'm about to head out there to the customer site (quite a distance away) if necessary, but I'd like to have an idea of what to try next--and also what might cause this type of problem.  TIA