More connectivity issues :(

So, I am having troubles connecting to the internet with my work laptop also. I have a Dell with Windows XP. When connecting ethernet cable from data port in the wall to home CPU, no problems connecting to the internet. But, when doing the same thing---connecting cable from data port into my laptop, I get the "Limited or No Connectivity" error message that says I can't access the internet because the network did not assign a network address to the computer. Now, why would it work when connected to our CPU and not to my laptop? Seems, that we can't access the internet connecting to anything else other than directly to our CPU (no internet access via wirelss router (read my other gripe on setting up our router) or laptop (can't even get connectivity). Uggg, I am really hating this OpenBand. We did not have issues like this when we used a modem thru Comcast service. Any ideas on how to fix this???