Newbie Question

["Kevin Stokes" <list@pieskysoft.com>]

  I'm a windows user who is trying to install debian, and I have a question:

All is ok until I  get to where I specify the APT configuration.  Although
my system is connected via a LAN to a cable modem, any attempt to ftp,
telnet, or ping anything besides 'localhost' results in 'Network is
unreachable'.

  If I boot Win95 on the same system, I can access the internet with no
trouble.

  My ultra-newbie question is:

What steps do I take to troubleshoot this?   Any help would be appreciated.

-Kevin Stokes