The keyboard stopped working on my Toshiba laptop

Hi everybody,
I have purchased Toshiba Satellite C55-A5384 recently with Windows 8. I was using the laptop extensively, but with care.
However, from yesterday my keyboard left unresponsive and I am unable to use it at all. But, the touch pad is working fine. I am not clear why it happened all of sudden.
Is there any setting That is causing this issue? I don't remember changing any settings. How to troubleshoot this kind of issues? Any help in this regard will highly be appreciated. Thanks for your time in advance!
