It is my guess that the working comptuer is connected via USB.  In my experience, cable and DSL modems with both USB and ethernet ports will automatically disable the ethernet port if a computer is connecting using a USB cable.

If both are using ethernet, however, then more testing would be needed.  A simple solution would be to get a router between the computers and the modem.

Thanks for your reply.  Both computers are connected via the built-in router in the modem.  And both are connected via DSL cable rather than USB.  The funny thing is that my old setup (Starsmart Modem and D-Link Router) worked just fine for both computers.  I replaced them due to a problem in the modem which slowed my connection down significantly.

Anyhow - after  working with Dell some more they determined that I couldn't flush the cache and that was the problem.  I ended up re-formatting and loading the OS and that fixed the problem.

I still don't understand why it worked fine with the other router and why this software problem showed up but I guess it's magic.  They couldn't explain it to me either (India Techs) so I guess I'll just be in the dark.

anyhow, it's working now.

Interesting.  Well, at least you've gotten it working now.