Wait! Don not erase the drive yet!
You will find many here who want to help for no charge.
Now thee will be some questions.
Did something happen to this laptop? Was is dropped?
Do you have another computer that can write a CD for testing?
IMO you should first test the laptop with a 'live' CD that will prove the laptop is OK. The 'Live CD' does not need hard drive space to run. So nit is a site way to confirm that the problem is with the hard drive and not other parts of the Laptop.
Also, a bookable USB flash drive can run some diagnostics.
http://www.easis.com/easis-drive-check.htmlDoes that help?