No Hard Drive Seen In BIOS

I have an old HP Notebook which suddenly died with the message "Operating System Not Found" displayed in a DOS screen. No amount of re-booting will alter this state, so after checking the BIOS settings and seeing "Hard Drive - None" I re-set this to "Auto", but on next boot-up it reverts to "None". Booting from a floppy works OK, once in, I can't access any drive but "A:\".
Is my hard drive fried? I've taken it out and shaken it around a bit before reseating but makes no difference. :cry

 

Thanks for the ton of replies to my problem fellow Geeks! (Total of Zero).
So for all the disinterested out there and for your boring entertainment, let me inform you that the problem was indeed a dead hard drive, and the only way for me to find out was to buy one (thanks Ebay) and try it. Everything is now back up and in working order. :major

 

good on ya mate, I hope my fellow geeks will help me better than they helped you. (so far, not good)