At this point, with the info given, as Mikecore says, we really can't help.
What's a minimal installation? Unchecking everything, including base? What did you do to set up your Internet connection afterwards? Were you using NetworkManager with X, or the command line.
As you haven't mentioned wireless, I'm guessing you are referring to a standard wired ethernet connection. Try to give a better description of the problem, and ask again.
What kind of ethernet card
(running the command /sbin/lspci should tell you, usually in the last two or three lines.)
Were you able to ping by IP address and not name? (For example, ping 4.2.2.2, it's a public address. If you can ping it by number, but not ping say,
www.google.com, it's a DNS issue.
When you can't connect, can you ping your gateway? Hrrm, someone oughta do a howto on the forums for a simple network troubleshooting guide.
If the light is on when you plug in the cable, see if you can ping the gateway, ping 4.2.2.2, ping google. If some of this works and other parts don't, you know it's a routing or DNS issue. If none of it works, the problem is a different one..
It can be difficult when you're starting out to know what information to post. Take a look at the forum guidelines, they have some good instructions for the best way to ask a question.