Test the hard drive to start with, and if it passes the test you can move on to trying other things.
Download your drive maker's diagnostic software for DOS
via the appropriate link here: http://www.tacktech.com/display.cfm?ttid=287
The download is an ISO file from which you can create a CD using IMGBurn
on a working computer:http://www.filehippo.com/download_imgburn/
Boot your laptop from that CD and the testing software will open. Test the laptop's hard drive using the "Long" or "Extended" test, with the laptop connected to mains power via the a/c adapter.