If any of the data is important to you, back it up immediately. Do this to a removable hard drive, CDs, DVDs or a USB drive.

Buy a new hard drive, something like this and reinstall your Operating System.

You should have a recovery disk that will take care of the reinstallation and all the drivers. You will lose any installed programs though, so you'll need installation disks or downloads to put them back. If you don't have them, you could always consider taking an image of your hard drive using something like Acronis True Image. This will copy your hard drive exactly as it is now. You then import the image onto the new drive and it looks exactly the same.

You need to find out if it's an IDE hard drive or SATA. What's the exact make and model of the laptop?