Can a virus corrupt a hard disk?

Shorter version:
Hard disk corrupt, vendor claims warranty does not apply since it was "due to a virus" and "problems due to software are not covered under the warranty".

Longer version: My Dell laptop recently refused to boot, and all attempts to 'repair' the Vista installation using the provided installation CD failed. I called up Dell support, and a representative took the laptop and after a day said the hard disk is corrupt. When I tried to ask for a replacement under the warranty, an official replied that the corruption was due to a virus, and "problems due to software are not covered under the warranty".

Now, I get a doubt that he's trying to avoid having to provide it under the warranty. Is it possible for a hard disk to get corrupt due to a virus? If yes, is there any way we can detect it was due to a virus (as he claims to have detected)?

Answer

This Dell technician is partly right. In the past, there were viruses which could damage a hard disk. They did this my moving the read-head of the drive to a sector outside the existing range, causing the head to bump against the internal frame of the drive itself, causing damage to the disk. But that was almost 25 to 30 years ago and hard disks have become more robust ever since.

Now, it is possible that something went wrong inside the BIOS settings of this laptop, thus the BIOS won't recognize the hard disk anymore, or just can't access it. This could be some virus trying to damage the firmware or just a user messing with the wrong settings. Restoring the proper BIOS settings should fix it, although you would need to know those settings first.

Finally, if you have warranty on the hardware then it doesn't exactly matter how it got damaged beyond repair. It is broken so they have to fix it. (Although you might want to check the warranty papers that you received with your purchase for exact details.) Do make it clear that you demand a replacement for this disk, which falls under the warranty. (Else, be prepared to ask for legal advise!)

I myself have a Dell desktop. I know they install their OS from a special disk image instead of doing an official setup. A regular setup would just format the disk, mark bad sectors and do a bunch of other stuff to make sure the disk is okay. Restoring a disk image won't do such checks but just does a quick format before putting the image back. If this fails for whatever reason, oops...