Its possible the hard drive may have been affected but not a certainty. Your only way of telling is to put it in another computer and try it. Are you going to rebuild this one?
Is the drive IDE or SATA? If IDE and you try it in an existing computer, I'd hook this drive up as a slave drive on one of the IDE channels.
I suppose you could also put the drive in an external enclosure and try to access it that way, but you're introducing some variables this way.