今天略微合拢了一下笔记本，然后Ubuntu unity死掉了，Ctrl-Alt-1进入terminal, 登录后重新启动系统，发现wif不能用了。
上网查了一个命令，可以检查软硬件禁用的状况：
root@dean-Latitude-3330:~# rfkill list 1: phy0: Wireless LAN Soft blocked: no Hard blocked: yes 2: dell-wifi: Wireless LAN Soft blocked: no Hard blocked: yes 3: dell-bluetooth: Bluetooth Soft blocked: no Hard blocked: yes
rfkill unblock all
好在笔记本上有键盘快捷键 Ctrl-F2，按下后解决了。
root@dean-Latitude-3330:~# rfkill list 1: phy0: Wireless LAN Soft blocked: no Hard blocked: no 2: dell-wifi: Wireless LAN Soft blocked: no Hard blocked: no 3: dell-bluetooth: Bluetooth Soft blocked: no Hard blocked: no 4: hci0: Bluetooth Soft blocked: no
rfkill - tool for enabling and disabling wireless devices
原文：http://blog.csdn.net/csfreebird/article/details/38131751