If the drive was bad, you would get a dialog at boot from the BIOS. No OS says clearly to me that the drive itself is ok but the MBR pointer to the partition is bad or the paritition itself is corrupt. IF you attempt to fix the partition with one of those tools, you may find everything is just fine. This might save whatever is precious on the HD, but if there's nothing of any import, ahh heck, just reformat and reinstall.