Unidentified Network - No Internet Access

Working with a Windows 7 Pro 64 bit OS. I set it up in my home and applied all the updates. Bought it to the persons house and hooked it up there and all seemed fine except after some time the computer could not access the internet anymore. The icon in the task bar stated "Unidentified Network, No Internet Access". I went back and went into Network Sharing and removed all the unidentified networks which there were 2 and connected once again telling Win7 that this was a Home Network. It all worked fine, logged off, shut down and everything came back fine. I thought all was good until about 4 hours later I get a phone call saying they have no internet access again and that the taskbar icon again states Unidentified Network No Internet Access. What can I do to resolve this?

Thanks in advance!!

It is set up wired. I'll post the IPCONFIG info when I take a trip there if I don't fix it then. Just trying to find ideas before I have to take a trip and come back again.

Thanks for the reply.

Thanks I will try removing the network card. The service is Cable modem and there are 4 other devices using it with no problems (wired and wireless). I will also recycle the modem if the latter doesn't do it.....

Thanks!