Enable WIFI again on Sony Vaio with Ubuntu 12.04

After installing 12.04 on my vaio laptop everything was OK. But when I disabled the WIFI from the Ubuntu menu the wifi showed an message that it was turned off with the hardware switch.

The weird thing: there is no hardware switch to turn off WIFI, neither does the BIOS have options for disabling the WIFI.

Doing a “rfkill list all”:

0: sony-wifi: Wireless LAN
Soft blocked: yes
Hard blocked: no
1: sony-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
2: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: yes
3: hci0: Bluetooth
Soft blocked: no
Hard blocked: no

After some searching I found a solution:

rfkill unblock wifi

Now your WIFI should work again.