"Enable Wireless" option is disabled in network settings

I'm using Ubuntu 11.10 (dual booted with Windows 7) but I'm unable to access Internet wireless even though I can do so on Windows 7.

The output for rfkill list all is given below:

rfkill list all 
0: brcmwl-0: Wireless LAN   
Soft blocked: no    
Hard blocked: yes
1: hp-wifi: Wireless LAN    
Soft blocked: no    
Hard blocked: no

The output for sudo lshw -C network *-network DISABLED is:

   description: Wireless interface
   product: BCM4313 802.11b/g/n Wireless LAN Controller
   vendor: Broadcom Corporation
   physical id: 0
   bus info: pci@0000:02:00.0
   logical name: eth1
   version: 01
   serial: 11:11:11:11:11:11
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
   configuration: broadcast=yes driver=wl0 driverversion=5.100.82.38 latency=0 multicast=yes wireless=IEEE 802.11
   resources: irq:16 memory:c2500000-c2503fff   *-network
   description: Ethernet interface
   product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
   vendor: Realtek Semiconductor Co., Ltd.
   physical id: 0
   bus info: pci@0000:03:00.0
   logical name: eth0
   version: 05
   serial: 22:22:22:22:22:22
   size: 100Mbit/s
   capacity: 100Mbit/s
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8105e-1.fw latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
   resources: irq:42 ioport:3000(size=256) memory:c0404000-c0404fff memory:c0400000-c0403fff

Broadcom STA wireless driver is installed, activated, and currently
in use.
My laptop is a HP-Pavilion-g6-1004tx.
My hardware switch is on.
Enable Wireless option is also disabled in network settings.

Solution 1:

If you can't repair your wlan interface, wifi network, you must do this:

First activate your wifi by shortkey of your computer (for example Fn+F2).

Then:

rfkill unblock all
sudo /etc/init.d/networking restart
sudo rm /etc/udev/rules.d/70-persistent-net.rules
sudo reboot

Now I have wlan up.

Solution 2:

A useful forum post points to the following actions as a solution.

First, run the following commands.

sudo modprobe hp-wmi
rfkill unblock all

Now, check if your card is still blocked.

rfkill list all

If it still doesn't work, hit Function F12 and see if 'hard blocked' changes to no. Also, try Alt F12.

If this still doesn't work, you can try using the open-source drivers instead of the proprietary ones. As mentioned here, the proprietary "driver is more likely to cause problems than to resolve them. Most of the problems reported by users on Broadcom chips are caused by this driver. Using this is HIGHLY NOT recommended. Before you even think of trying out this one, make sure to try the other drivers first."

So, let's do that.

echo 'blacklist mac80211
blacklist brcm80211
blacklist cfg80211
blacklist wl
blacklist lib80211_crypt_tkip
blacklist lib80211' | sudo tee -a /etc/modprobe.d/blacklist.conf

sudo sed -i '/exit 0/i \
modprobe brcm80211' /etc/rc.local

This will load the open-source driver module at the end of each boot process.

Kudos to jokerdino for this one.