Don't jump to the conclusion that it's the hard drive unless you have run the extended hard drive diagnostics and tried other tests. It could be some other hardware or software failure. Explain what you have done so far. Did you try to boot to your operating system disk to see if you can do a Repair? Six days out of warranty, you might be able to get Dell Support to help diagnose the problem without a fee.
Well, it was bound to happen, but 6 days after my warranty expired, the computer stopped working! I have since figured out that the hard drive is corrupted and that I will need a new one. All of my data is backed up, but I have never replaced a hard drive before. Can anyone offer help in terms of the steps I need to take, critical things not to do?