Hard disk failure when tried to reboot

Hi,
I am using dell desktop. I update windows regularly.
A few days ago when i was updating windows, my pc froze in the middle of updating.
Then i tried to reboot the computer. I was unable to reboot the computer.
Then i run a hard drive diagnostic test. It showed this message:
"Hard drive failed the test: run code 7."
How can i solve this problem?
Please Help.
