2cents of opinion that dosn't matter, I would rather take 80.00 instead of buying spinrite or another HD software program and buy a extra HD and use either a full back up, incremental, or a differential backup. ( or ghost, acronis and make a shadow copy)
I would rather make a disaster recovery plan then to sit and run a program to see if my hardrive is going to die, I have to many irons in the fire to sit and analyze my HD. (thats just me though)
I have used chkdsk to fix corrupt data on the boot, because my computer would not start.
The problem ended up being memory corrupting my drive.
I am not saying that chkdsk will fix all problems either.