Scandisk is a dos utility that will do a quick or full check of every sector on your HD and if possible repair them. Do you have a boot disk that will get you to dos mode? If not. Do you have another computer with the same OS that you could use to make a boot disk.
It's possible that you can find a utility on the net that will allow you to boot up in DOS mode so you can check your disk.
HD's are fairly cheap at newegg or geeks. I just bought a new 40 gig for 36.00. Best of luck.