Today, I've created a bootable USB of Ubuntu 12.04LTS.
When I booted it, everything seemed to work, and knowing well this distribution, I installed it rapidly. During the installation, it losts the connection and isn't able to find it again! (neither network-manager will find a wifi module) Well I decided to finish the install and when I rebooted, my OS doesn't have any internet connection available.
this command will show up "eth0" and "lo" both are written as "no such entry" (or something like this, I have a dual boot with Windows, I'm currently on my windows OS)
Well I decided to boot again my bootable USB with Ubuntu 12.04LTS, connect to the internet and then use the command
There, appeared an other entry called "wlan0" beside the two other ones (still desactivated) with SSID name and, well, everything in order. Then, appeared the additionnal driver notification, saying I have to install the broadcom BC43XX driver for wifi, what I did, and before it ends, I lost the internet connection again.
Then, the iwconfig command will only show up the "eth0" and "lo" entries, and no "wlan0" one...
I will add that on this computer I had ElementaryOS, which is based 12.04LTS and everything was working just fine (with or without the proprietary driver.)
EDIT : I noticied that I can use internet connection till I try to install drivers or the system. anyway I'm now on Ubuntu 13.10 (Cause I couldn't manage to make the wifi work)