Registry edit killed Windows (W2K)

[Richard99]

I had a problem with a USB connection where Win2k repeatedly tried to reinstall it even though it was working fine.
After getting advice in the Drivers forum I decided to remove all references to the device in the registry and do a clean install.
Regedit wouldn't allow me to remove the USB key from CurrentConfig, but after reading all the relevant advice I got a copy of Resplendent which allowed me to remove the key. But as the key was deleted I got a Windows message to say that 'the program' had crashed and I would have to re-start it. No problem, I thought - I had taken a full registry backup and if anything has gone wrong I can replace it.
But when Windows re=starts I get a blue screen message
STOP: c000021a {Fatal System Error}
The Session Manager Initialization system process terminated unexpectedly with a status of 0xc0000022 (0x00000000 0x00000000). The system has been shut down.
If I re-start in Safe Mode, I get exactly the same message. If I choose Safe Mode with Command Prompt, I get the prompt and can move around with DOS commands. But I'm not sure what that achieves.
The machine is a Sony laptop that comes with an 'image' disk. If I reinstall Windows from this I will have to start from a clean disk and reinstall all my apps, networking settings, etc which is probably a couple of days' work. I have backups of all my critical data but there are still many apps to install and configure.
I have a standard Win2000 disk for another machine, and booted the PC with that. Selected Repair. It ran through properly and told me that Windows had been repaired. But I still get the STOP message when I re-boot.
Do I have any chance of recovering from this position, or should I start right away with a clean install (I really don't want to do this!). I need the PC working fully for a business trip on Monday and I would probably have to spend the whole weekend rebuilding it. I need to make a decisiom real soon.
Please help!

[Andy-S]

Have you tried the last known good?

To troubleshoot Stop error 0xC000021A
Remove any newly installed hardware (RAM, adapters, hard disks, modems, and so on).

If you are unable to log on, restart your computer. When the list of available operating systems appears, press F8. On the Windows 2000 Advanced Options Menu screen, select Last Known Good Configuration, and then press ENTER.

Run Recovery Console and allow the system to repair any errors that it detects.



Cheers
Andy

[Richard99]

Andy

Yes, I should have said that was the first thing I tried - Last Known Good. I rebooted and got the same result, and that was when I tried the Recover.

I saw all the notes on the blue screen about removing new hardware, but there was nothing to remove. It's just a laptop with its usual configuration. The only new thing was the USB connection to a Palm that I was trying to trouble-shoot. And naturally I disconnected that before removing the drivers. So there's nothing new to remove.
Do you have any other suggestions?

- Richard

[Andy-S]

That's unusual that the last known good didn't fix it if it was a registry problem.

Have you tried booting to the command prompt and replacing C:\winnt\system32\config\system with c:\winnt\system32\config\system.alt. Rename the system hive to system.old and then rename the system.alt to system (no extension). I'm not sure if you will able to do this as the system hive may be in use.

Cheers
Andy

[Richard99]

Andy
I've tried to do that. Unfortunately I can't now boot into safe+command prompt. I did that a couple of times before, but now I get the same blue screen message with every F8 option.
If this isn't a registry problem, what could it be?
Do you think I should give up and reinstall everything?
- Richard

[jdharm]

Here's a crazy idea. I don't hold out much hope for it, but I can see how it might work.

You said the crash happened when deleting something pertaining to USB. So, disable the onboard USB from the BIOS and reboot. Maybe if the USB isn't present then the OS won't make an issue of any problems you induced.

MAYBE

(that's a big 'maybe')


Josh

"It is easier to stay out than get out."

[Richard99]

Well, here's the latest..
1. I realised that I could get a command prompt by plugging in the bootable floppy drive (this is a laptop), and booting from a DOS disk.
I used that to change to the system.alt file as suggested, but this made no difference - still the same blue screen.
2. I followed up the USB disable suggestion, but the BIOS on this thing doesn't allow you to disable USB. You can only play about with the USB "legacy emulation". I tried that of course, but no joy. It was a good try though.
Thank you both for your suggestions, but it looks now as if I'm going to have to reinstall from a clean disk. I'll just wait a bit for any last brainwaves. Bang goes the weekend, I've got 30GB of apps and data to re-install and configure.
- Richard

[Richard99]

Josh and Andy,
Just to let you guys know that I finally took the plunge and wiped the disk. Half of the apps loaded now. The original USB problem has gone away with the clean install. Biggest problem now is remembering all the settings to talk over DUN to my office network ...

Thanks very much to both of you for taking the trouble to make helpful suggestions. This is a nice place to come.

- Richard