If you tried Ubuntu on a live Cd everything works out of the box. Some problems could arise after installing the operating systems and sometimes network manager is not able to manage the wifi connections. This happens because Network Manager doesn’t manage network interfaces by default, but expects for some other application to do it (eg. ppoeconf). So to solve this annoying problem you have to:
- Open the the terminal (CTRL + ALT + t)
- Type cd /etc/NetworkManager
- Type ls -lsa this gives you a list of the files in the folder; you should have one between the following two: NetworkManager.conf or nm-system-settings.conf depending on your Network Manager version.
- Type sudo nano /etc/NetworkManager/NetworkManager.conf or sudo nano /etc/NetworkManager/nm-system-settings.conf
- Look in the code for manage=false and change the value to manage=true
- Save and reboot, your Network Manager should recognize all the Wi-Fi networks!
If you prefer to use the default text editor gedit, change sudo nano with sudo gedit