You can start it in Safe Mode perhaps? Can you use System Restore to go back to before this happened?
How to boot Windows 8 into Safe Mode http://www.eightforums.com/tutorials/2757-safe-mode-start-windows-8-a.html
How to use System Restore in Windows 8 http://www.eightforums.com/tutorials/4692-system-restore-how-do-windows-8-a.html
Best to contact Technical Support as normally a pin is associated with Mobile Products not regular home products.
It would be of immense help if you could take a snap of the screen using camera and post the same here!
Selvan do you think it could be Anti theft 2 doing this?
Hi Tony as far as my knowledge AT doesn't ask for a PIN (but will ask a recovery code) however we'll be able to figure out only when sidney1972 posts the image of the locked screen.!