As Hotdog said, can you hear ticking from the drive? If it's ticking then it's pretty much a goner, You COULD do what Hotdog said and take it apart, However, if ONE SINGLE SPEC of dust gets in there, it can ruin the drive. (though if it's ruined then i suppose there is no worries eh?)
Have you tried to pull it out and reseat it? If the laptop was dropped maybe the drive pulled loose, not as common with todays laptops, But 05 and back it can happen.
If you have a SATA drive and pull it out and connect it to a new PC, can the other PC read it? could be the impact damaged the motherboard, not the drive.
And again to quote Hotdog, if it's something you can't live without, BACK IT UP. hard drive failure is a real thing people don't think about.