if your hard drive is corrupted then you have no luck gettin it back..once its gone its gone forever BUT I dont think thats what happened...If you could provide more information then we might be able to help
could have been a power surge that might have overloaded your comp :D and then all hell broke loose inside and BAM..its dead...take it to a store or ask a smart comp friend to help..
my day is sorta bad..I spend from 1.:42 to 4:30 driving out to elementary schools installin PDA software ect just for the comp to screw upl..lol good thing its not my comp.