http://ubuntuforums.org/showthread.php?t=2190347
正文：
Thinkpad Edge E440 安装 Ubuntu12.04 后 无法使用无线网卡， 须要手动安装驱动。
下载驱动原码编译安装：
sudo apt-get install build-essential linux-headers-generic
下载：http://netbook-remix.archive.canonical.com/updates/pool/public/o/oem-wireless-rtl-92ce-92se-92de-8723ae-88ee-8723be-92ee-dkms/oem-wireless-rtl-92ce-92se-92de-8723ae-88ee-8723be-92ee-dkms_0017.1016.2013~sutton1.tar.gz
解压到：~/Desktop/
cd ~/Desktop/oem-wireless-rtl-92ce-92se-92de-8723ae-88ee-8723be-92ee-dkms-0017.1016.2013~sutton1/oem-wireless-rtl-92ce-92se-92de-8723ae-88ee-8723be-92ee-0017.1016.2013~sutton1/driver
make sudo make install sudo modprobe rtl8723be