stop: c0000221 unknown hard error on blue screen

My son was using my Thinkpad R51 when he got this screen. The rest of the
message was; SystemRoot/System32/ntdll.dll. I understand that this means
that my ntdll file is probably corrupted. After the fact, my son mentioned
that he had briefly seen a "Dumping physical memory" message on a black
screen, before it went blue. The computer will not start. The boot up
process goes to through the bios screen, the screen to select the mode of
booting (safe, safe w/command prompt, etc., the Windows XP banner screen,
then it goes blue.

My other son, who used to own this laptop, lost the original XP cd's, so I
have no original software with which to try a recovery/restore/repair.
Lenovo recommended PC Dotor 5, but I cannot get it to load from the CD burner.

I'd appreciate any insights or help.

That message usually means a defective hd,or soon to be.At this point,w/o
the xp cd youre pretty well stuck,if it was mine & had access to another
pc,i'd
download & install to a MS-DOS formatted floppy,the hd DOS hd utility.Get
it only from the hd mfg web site,boot pc to floppy,run the test(s).If the hd
has failed by test results,then it would at least narrow youre next move...

"John" wrote:

> My son was using my Thinkpad R51 when he got this screen. The rest of the
> message was; SystemRoot/System32/ntdll.dll. I understand that this means
> that my ntdll file is probably corrupted. After the fact, my son mentioned
> that he had briefly seen a "Dumping physical memory" message on a black
> screen, before it went blue. The computer will not start. The boot up
> process goes to through the bios screen, the screen to select the mode of
> booting (safe, safe w/command prompt, etc., the Windows XP banner screen,
> then it goes blue.
>
> My other son, who used to own this laptop, lost the original XP cd's, so I
> have no original software with which to try a recovery/restore/repair.
> Lenovo recommended PC Dotor 5, but I cannot get it to load from the CD burner.
>
> I'd appreciate any insights or help.

Thanks, Andrew E. I ended up taking it back to my local Lenovo warranty
service center. They figure that it's a software corruption, and they are
backing up my files re-loading the OS. I will start looking for another HD
though. I'll backup often and prepare for the inevitable failure.