trying to fix a machine with this problem on bootup:

STOP: 0xC0000221 unknown hard error
C:\Winnt\System32\Ntdll.dll

it's a dell dimension 8400, 3.4 ghz, 160GB hard drive, 512 MB ram, i
think running sp2, but since i can't get it to boot, i'm not sure. no
new hardware was installed recently, although she did say she had
upgraded skype.

so far all i have done is get the data off the drive, by booting the
machine with a linux live CD and burning it to DVD, so i'm good to go
as far as erasing the drive if need be. however, that showed me that
the drive was there, and that the data was intact. unfortunately it
could only mount the ntfs partition read-only, so i couldn't copy the
uncorrupted ntdll.dll onto the drive.

i have read this page:
http://support.microsoft.com/default...;en-us;Q314474

when i put in an XP cd to run the repair utility, it says that there's
no hard drive in the system.

since booting with the CD means i can't get to the hard drive, i'm
having kind of a hard time trying to figure out what my next step is in
diagnosing the problem, since i don't have another known-good hard
drive available to test in the machine.

so the question becomes: do i buy a hard drive and see if a reinstall
works? or--what i'd prefer--is there another way to test if something
else is wrong with the machine before trying that? because i don't
want to tell her to get a new hard drive and reinstall xp, and then
have a motherboard problem or something fry her new hard drive as well.
are there other diagnostics i can run without being able to fully boot
xp?

thanks for any help anyone can give.

Jaymon wrote:
> If you can get the affected HDD, installed as a slave in another XP machine
> and it is seen or shows up as unallocated in disk management, you might be
> able to use TestDisk to repair or write a new MBR.. It may allow you to
> repair or replace the bad .dll on the spot or at least allow the drive to
> boot, once it's back in her machine..
> http://www.cgsecurity.org/wiki/TestDisk
> May be worth a try, your call..
> Hope it can help..
> cheers


thanks jaymon--I'll give that a shot.

Jaymon wrote:
> Be sure to post your results or concerns, inquiring minds and all that, you
> know..
> Cheers


ok then. i decided that before i would bother with swapping out
drives, i would try replacing the file. so i used that system rescue
linux (sysresccd.org) and ntfsfix and ntfs-3g to force the funky
partition to boot, and downloaded the dll from dll-files.com and
replaced it.

i rebooted into safe mode, and things hung checking out some
agp-related cfg file for a good long while, but i let it run. it
rebooted itself normally, and things were fine.

and then i got the message from the system tray "your new hardware is
installed and ready to use" and another message saying 'your new
hardware is installed but you need to restart'. which i did.

and now everything's acting normal.

now, she didn't mention installing hardware--if she did i would have...
ok i would have done the same thing, but i would have had more of a
clue--a bunch of the research i did to solve this mentioned that it can
be caused by installing new hardware, especially on the SATA cable. i
looked at the device manager but nothing jumped out at me as new.

so basically i'm giving her back her machine with a warning about that
sort of thing--i mean, if hardware conflicts caused the problem, that's
a different story from a bad hard drive, or anything. but either way
she should be keeping a close eye on her hard drive and backing up
regularly...

anyway thanks.