My experience with a corrupt Windows XP registry

I just had a major incident with the XP registry. I researched my
particular problem quite thoroughly on the web and using Google's
newsgroup search, but I didn't find anything that solved the problem
directly. The story has a happy ending though, so I figured I'd take
a few minutes to type it up. Maybe it will be useful to someone.

Here are the specs of the system:

AMD Athlon XP 2800+
Asus A7N8X Deluxe motherboard
1-gig of TwinX Corsair RAM
Promise SX4000 IDE RAID controller
three Western Digital 120-gig "special edition" hard drives
Windows XP service pack 1

The hard drives were configured in a RAID-5 setup. That's roughly
240-gigs of storage. Any one of the three drives could fail and the
system would still function. The 240-gigs were divided into 18 drive
letters of various sizes. This system is used mainly for audio
editing projects and I like to keep each project on a separate
partition. All of the partitions are NTFS.

My systems usually run 24 hours a day. I have United Devices
configured to run in the background and it's well behaved. I rarely
ever need to put it in "snooze" mode or close it. Plus, I can cash in
my UD credits for download credits on Easynews.

One morning I woke up to find the computer off. I thought a friend of
mine might have absent-mindedly turned it off, but that was not the
case. I tried booting the system and got a blue-screen registry
error, something like:

0x51 "Registry_Corrupt"

From here on I'll call this the 0x51 error.

I tried "Last known good configuration" and got the same 0x51 error.
I also tried "Safe mode". Same thing. Uh oh.

Turns out that the fancy TMD (tip magnetic drive) fan that I had on my
CPU had freaked out in the middle of the night, randomly spinning up
and down, causing the processor to overheat. Either the scorching
processor or the motherboard suddenly shutting itself down damaged the
windows registry beyond repair. We're talking a TOTALLY trashed
registry.

Most of the replies to people on the USENET with the same problem
referenced the following Microsoft page:

http://support.microsoft.com/default...;en-us;Q307545

I did not have the recovery console installed, so I booted from my XP
disc and ran it from there. 0x51 error as soon as it tried to access
the registry.

So I figured, ok, I'll probably lose some stuff but I'll just install
XP over the existing installation so I'll have access to my data
again. As soon as the XP install looks for a previous installation of
Windows, guess what? 0x51 error again.

The Microsoft support page had all of the information that I needed to
know to repair the registry manually. I just couldn't get to the NTFS
drive to do what I had to do. I could always wipe the C: partition
and install XP from scratch, but that would be a major hassle. There
just had to be a better way.

On a conventional system you might suggest removing the hard drive and
putting it in another 2000 or XP system temporarily. My Promise
SX4000 RAID controller and hot-swap kits made that impractical, so I
did the next best thing. I stuck an old 4-gig hard drive in the
system and pulled the RAID controller just out of its PCI slot, then
installed XP fresh. I did the F6 thing to install the RAID driver
too. Once XP was running on the old 4-gig, I powered the system down
and inserted the RAID card once again. I had full access to all of my
drives and I was able to follow the gist of the Microsoft guide to
copy the five registry files from my System Restore Volume to the
windows/system32/config folder. I then pulled the 4-gig out and set
everything back like it was before the incident.

The system now booted right into XP without errors, but the screen was
in 16-color mode or something for some reason. It didn't matter at
this point, though. The next thing to do was to run the system
restore utility and REALLY turn the clock back to my last working
state, which was about a week old. Another reboot and a couple of
Norton Disk Doctor scans and the machine was up and running, good as
new. The only thing missing was an desktop icon for a game demo that
I had installed within the last week -- a two second fix.

If you use encrypted files and folders you will not have access to
them while you're using the temporary hard drive UNLESS you've
archived your encryption data somewhere. If you manage to recover
your registry the way I did, your encrypted folders should work just
as they did before.

I hope this helps someone down the road...


-Wuahn