corrupt hard drive

My Dad's gone and wrecked his hard drive by shutting down while running Norton Antivirus. After that he kept getting the blue screen of death. There wasn't anything to back up, so I just went straight to fdisk to completely repartition and reformat it, but his 160GB drive was only showing up as 21.5GB. I checked this with the partitioning software from windows XP and Debian Linux and both of those recognised the full drive. I partitioned it into two 80GB partitions with XP and went back to fdisk which told me that there were two 40GB partitions and the total disk size was 21.5GB. I used sys C: from win98 boot disk and MBRtool to replace the master boot record and tried fdisk again but still 21.5GB. I just downloaded Activ@ Killdisk from here and zeroed the entire drive but it still shows up as 21.5GB on fdisk.
I'm beginning to suspect a head crash or some other mechanical failure but only DOS based stuff has a problem with the drive. Also I don't really want to tell him his drive's dead. He's only had it a few weeks and didn't keep the receipt like I told him to.

His PC:
AMD Athlon 2000+
A Bit VA-20 mainboard
384MB RAM
160GB Samsung hard drive
Windows 98