BSOD, NVSTOR.SYS message

Hi Everyone;

                                                      i am new to the community, this is my first post.  I have a Dell XPS 630 which up to 2 days ago was operating perfectly.  When i booted up, I got the BSOD with the message:

                                               DRIVER-IRQL-NOT-LESS-OR-EQUAL           followed by     NVSTOR.SYS.(address 8b604395 base at 8b600000, datestamp 46671a61.

        I cant boot in safemode, nor in LAST KNOWN GOOD CONFIGURATION.  I attempted to do an OS repair install, booting from CD, but always get the blue screen. 

    I ran the diagnostic after hitting F12 key. At the harddrive DST short test, it showed error code 2000-0141 , hard drive not detected. If i hit F2 and go into setup. it dosent see the hard drive , shows as NONE.  What could have happened, it was fine when I last shut it off. How can the hard drive fail with NO WARNING OR SYMPTOM???

     Has the hard drive failed?  Would a driver be the problem? What are my options?  Any help would be appreciated