chkdsk saying unrecoverable errors

my dad called me this morning saying his computer (windows xp) won't boot and it keeps getting to a screen saying "disk error, hit ctrl+alt+del to reboot". So I got him to the recovery console and ran fixmbr but got the same error. Then I had him run chkdsk /r, but he said it got to 25% and then said there were unrecoverable errors. He has another drive that I could have him install windows on and then try to access his old drive to copy files off, but is there another way to fix the unrecoverable errors? even if I am able to boot off another drive, will I be able to see the files on the old drive or is the filesystem (NTFS) messed up? I'm helping him over the phone since I am 2 hours away so I don't want to take him thru a mess of steps if they aren't going to remedy the situation.

My first thought is...HDD failure...

Did you ask him if he is hearing the click of death?

It still might be possible to get the info off the old disk...but its about a 50/50 chance if the HDD is pretty close to being trashed...

he doesn't hear an clicking or whirring or anything. I'm fairly certain the filesystem got screwed up somehow. He said it was working fine all day yesterday and he shut it down completely last night when he was finished using it. So sometime between shutting down last night and booting this morning it got messed up.

I started walking him thru doing a new install on the new drive, and when he gets to the screen where he selects the drive to install to, it shows C: but says it has an unknown filesystem and is completely free space. Luckily, I trained him to save documents to a 2nd hard drive, so I am confident that formatting and reinstalling windows won't lose any crucial data. Its just a pain having to walk him thru reinstalling everything over the phone.

well, I'm guessing his main drive is completely hosed. we tried installing xp to the secondary drive (unplugged the main and made the 2nd drive the primary master) but the xp install kept saying it was a dynamic partition with 0mb free, so today I had him download Ubuntu and boot in to the live environment which allowed him to see the contents of the 2nd hard drive and copy files off it to another computer. He hasn't plugged in the 1st hard drive again yet, but i'm not too optimistic about if he will be able to see the data on it. I'll have to research some data recovery options to see if there might be anything on that 1st drive we want to back up.

It's likely a HDD failure. I had the same thing 2 years ago. I had the drive backed up so I just formatted and re-installed.
No clicking noises either, just constant cycling.
I bought a new drive.