I already answered the other guys question and my answer will be just as relevant here
Unable to connect WiFi in Ubuntu 12.04
Classic problem, For your OS to understand what to do with your
hardware you need something called a driver. it is a peice of software
that tells your computer what to do with your hardware (wifi drivers,
bluetooth you name it) they cant include it all by default so what
you're gonna have to do is,
Plug your laptop into your Ethernet cable. Go open terminal and type
sudo apt-get install jockey Put in your password (You wont see the
password your typing for security reasons) run it, download all the
drivers it asks you too. Reboot
This should work for you, but if jockey didnt detect anything then go
to wirless.kernal.org and look around there try jockey first, its
easier. Hope this helps.