[SOLVED] Wireless Network Detected But Unable To Connect Under Ubuntu 12.04/11.10

If you can't connect to wifi networks and the buttons for connecting/enabling a wireless network are grayed out in your Network Manager indicator under Ubuntu 12.04 (Precise Pangolin) or Ubuntu 11.10 (Oneiric Ocelot), this means that your wireless network is disabled by hardware/software switch. This problem is common for users of laptops.

To check if there is a block on hardware/software of your wireless network, we need to run this command from the terminal:

rfkill list wlan

or

rfkill list all

Here are the outputs returned for my example:

~$ rfkill list all
1: phy1: Wireless LAN
Soft blocked: yes
Hard blocked: no

As you can see from the example above, I can't connect to the wireless network because software is blocked. To unblock it, you need to use one of these two commands:

rfkill unblock wlan

or

rfkill unblock all

Finally, restart your network manager with this command:

sudo service network-manager restart

You can now connect smoothly to WiFi networks.

PureOS 6.0

Marc Poirette has announced the release of PureOS 6.0, a desktop Linux distribution with GNOME 3 based on Debian's "testing" branch: "PureOS 6.0 is a multilingual live CD/USB based on Debian 'testing' with GNOME. Supported locales: FR (France, Belgium, Canada, Switzerland), EN (USA, United Kingdom, Australia, Canada, Denmark, Ireland, India), others (Brazil, Czech Republic, Finland, Germany, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Romania, Russia, Spain, Sweden, Turkey). Main features: Linux kernel 3.5.3 and GNOME 3.4.2 (GNOME Shell + GNOME Classic). Internet: Chromium 21.0 with Flash player. Multimedia: GNOME MPlayer. Graphics: Evince and Eye of GNOME. System: GParted, smxi/sgfxi scripts, scripts for modules management: activate, debs2lzm, debs2lzm-file, dir2lzm, lzm2dir and find2lzm. The release announcement includes the full package list and a list of download mirrors. Get the live CD image from here: PureOS_60.iso (683MB, MD5).