I have a Sony VAIO laptop and recently installed Ubuntu 12.04 along with win 7, dual boot! I have wifi which works on windows but on Ubuntu , my wireless is disconnected. I typed "rfkill list " on the terminal to check the reason for the problem and it shows me that my "acer-wireless:wireless LAN"is soft blocked and its not hard blocked. I tried clicking on the enable wireless option on the top left of the screen after logging into Ubuntu 12.04 but it is not getting enabled. Please help ,as I need to download eclipse for programming in college.
sudo modprobe -r acer-wmi sudo rfkill unblock all rfkill list all
Now is your wireless working? If so, let's blacklist acer-wmi:
sudo su echo "blacklist acer-wmi" >> /etc/modprobe.d/blacklist.conf exit