One day when I switched on my dell inspiron 600m notebook, before booting up it started asking the hard disk password. Now I have never set up a hard disk password on my laptop so  was amused after seeing this. After switching it on and off for two to three times I was able to boot up my laptop.

 

However after few days I again started getting the prompt for hard disk password and this time laptop didn't boot up even after switching it on/off two three times. Everytime it was showing hard disk password screen, as I haven't set up the password I was not able to pass through the screen. Could you help me out in this problem?