Recovering from a corrupted Windows Registry

This is a post about how I recovered from my corrupted Windows Registry. I’ll be the first person to admit that I’m the person that also corrupted said registry.

I ruined my registry the normal way, delete registry key chunks with Regedit.

I had installed Oracle 11 directly onto my development laptop to perform benchmark testing of some performance improvements that were planned to be developed. But that was months ago, and that project got lost of the prioritisation list almost as soon as it was added. Full Oracle 11 does not have an uninstaller, which seems like a crime to me, but I guess they think if your going to all that effort to install it, you most likely want to use it. Which for businesses this makes a lot of sense, except when you want to tinker and experiment, and as it’s free for developers, they are the most likely to be the tinkering group, but as they are the only ones likely to want an uninstall and they paid nothing there is not much ROI on developing an uninstaller.

So I was getting rid of Oracle the nip ‘n’ tuck method, but I got bored, and just started cut ‘n’ slashing. There were only one set of edits that were dubious, that was trying to delete a node called Session Manager.

Turns out that you get an error message half way through deleting the key/node, and you are not allowed to delete that!, but you have also lost some of the values/keys.

In hindsight, this would have been a good point to run System Restore, to fix my mistake, before rebooting….

But I rebooted, and the machine then BSOD under all boot methods.

Googling for the error message gave me some good solutions, one being the excellent KB 307545 How to recover from a corrupted registry that prevents Windows XP from starting.

Only problem I had no install media, and I was at located at different company on the other side of the planet from my IS department.

I Tried booting my Dell Latitiude E6400 from genuine Windows XP Pro media (found by driving 30minute to a different work location), but that also BSOD (but different type).

Built an USB bootable XP Recovery Console but it could not see my internal hard drive.

Finally got in touch with the New Zealand IS team once they come on-line and initially got the “oh that’s nasty, sounds like your hosed“ response, but was place in queue for the time with the chief/grumpy IS head dude/wizard to call me back.

Luckily he had solved this before, and pointed me to the above mentioned KB article, but added “you will have to use Dell install media to boot into Recovery Console, as that will have the needed Dell driver built in“.

Meanwhile the host companies IS team got back to me with the “oh that’s nasty, sounds like your hosed“ answer, but they agreed to  tried all their magic boot CDs and things where still “oh that’s nasty, yip, your hosed“. I begged for a Dell disk, and with much disdain it was tried, and you know what, it worked. He miss-followed the above instructions, and repeated the IS mantra “oh that’s nasty, yip, your hosed“ when it didn’t work. But he did burn me a copy of the media, and said “your welcome to try it yourself“.

Which I did, and step by step, rebuilt my registry, thus got my machine back up and running.

Only 24 hours of down time.

We are in the middle of the craziest crunch I’ve seen over the last four years of working for this team, so timing wise this was bad.

I’m very glad it’s over really.

I still have Oracle installed, but for now I’ve disabled all the services and will leave it alone, it can wait till a controlled repave.

I also think I’ll invest in a external back-up process, as I’m now off-site and on my own, not really wanting to have to ship my lappy off to have it repaved and lose all my data/etc. I had been quite use to being cavalier with my PC because the on-site IS team were great, and things could get fix quickly, but now I may have to be a little more cautious now I’m flying solo.

Overall I am very impressed with the recovery tools built into XP, and while they are a little voodoo, I’m glad they are there, and well documented. I just hope I never have to use them again.


Conor 2010-02-11 12:20:28

Soooo you’re still alive. How’s it going over there?

Simeon 2010-02-11 14:58:06

Yes, I’m still here.