CAPS LOCK shuts down the computer immediately

I have discovered this problem with my Laptop, today itself. No matter what the environment, app, screen is, as soon as I press CAPS LOCK key, the computer shuts itself down abruptly (abnormal shutdown, like power failure).

It can again be tued on normally though, using power button.

I Googled a bit and discovered that CAPS LOCK is used as CRUISE control so it shuts down the laptop in-case it is not cool enough. My laptop is cool enough.

Following are the environments, in which I've tested this abnormal behavior of CAPS LOCK (abruptly shutting down my machine)

1. GRUB
2. UBUNTU 16.04
3. System Testing (F12)
4. Windows 8
5. Pressing CAPS LOCK on on-screen keyboard
6. Exteal Keyboard's CAPS LOCK

My laptop is Dell Inspiron 3542. Thanks