I'm not able to enable Wireless using the hardware switch on my HP ProBook4430s.

Because of this the Enable Wireless option is greyd out and I cannot enable it.

The greyd out option can be seen in the screenshot below.

The results of iwconfig for my system are as follows,

lo        no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=off   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

eth0      no wireless extensions.

Also I tried to do the following,

    sudo ifconfig wlan0 up

but I got an error as below,

    SIOCSIFFLAGS: Operation not possible due to RF-kill

Also the result of sudo rfkill list all for my system is as follows,

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

How do I fix this problem?

Thanku!