Corrupted Registry and Unable to Boot

[Guest]

Help!

I was working with the registry file and managed to disable my computer. I
searched this site and all related posts I found point to KB 307545. Problem
is I have an OEM operating system installed and the KB warns against
restoring hive files in this case. Moreover, my copy of XP is on a DVD and I
am not sure I can boot to this drive anyway.

Prior to editing the registry I saved a copy to another folder. My question
is is there any way to get to this backup version of the registry and restore
it without using hive files? Would booting to DOS allow for this? I
understand sysinternals has an NTFS add-on for DOS. Otherwise, could I
somehow use the recovery console to restore the registry from the saved copy
(assuming I can start the console from the XP DVD)?

Thanks in advance,

Harris

 

[John John]

The problem may or may not affect your installation. You can use the 6
floppy diskette set and boot to the Recovery Console with those. The
floppy set has been fixed to work around the OEM password problem that
you mention. http://support.microsoft.com/kb/308402 Now, I suppose you
will post back saying that your pc doesn't have a floppy drive... ;-)

John

 

[Pegasus \(MVP\)]

Help!

I was working with the registry file and managed to disable my computer.
I
searched this site and all related posts I found point to KB 307545.
Problem
is I have an OEM operating system installed and the KB warns against
restoring hive files in this case. Moreover, my copy of XP is on a DVD
and I
am not sure I can boot to this drive anyway.

Prior to editing the registry I saved a copy to another folder. My
question
is is there any way to get to this backup version of the registry and
restore
it without using hive files? Would booting to DOS allow for this? I
understand sysinternals has an NTFS add-on for DOS. Otherwise, could I
somehow use the recovery console to restore the registry from the saved
copy
(assuming I can start the console from the XP DVD)?

Thanks in advance,

Harris

Saving a copy of the registry was a good idea. Unfortunately
you only went half the distance by not considering how to restore
the backup copy. I also wonder what exactly you mean by
"saved a copy". How did you get around the fact that the
registry is locked while Windows is active?

There are several ways to restore a registry file:
- Use John's method, involving 6 floppy diskettes.
- Boot the machine into the Recovery Console, using a WinXP CD.
- Connect the disk as a slave disk to some other WinXP PC.
- Boot the machine with a Bart PE boot CD.

 

[Guest]

Thanks guys.

John- I have neither the floppy diskettes nor a drive...

Pegasus-
Where do I find a WinXP CD? I only have an XP DVD. The slave disk is a
good idea but I will have to find another computer first (this process sounds
painful but a good last resort). Finally, what is a Bart PE boot CD? I will
Google for additional info.

To answer your question, I exported the entire registry with regedit as a
..reg file.

Harris

 

[Pegasus \(MVP\)]

See below.

Thanks guys.

John- I have neither the floppy diskettes nor a drive...

Pegasus-
Where do I find a WinXP CD? I only have an XP DVD.

This is news to me. I thought all WinXP installation media
are CDs, not DVDs. Still, if you can boot your machine with
it then it's fine.

The slave disk is a
good idea but I will have to find another computer first (this process
sounds
painful but a good last resort).

Finally, what is a Bart PE boot CD? I will
Google for additional info.

A Bart PE boot CD is a very powerful tool for administrators.
Unfortunately it takes another PC to make one, plus several
hours of solid effort.

To answer your question, I exported the entire registry with regedit as a
.reg file.

This type of backup is of very limited use. A proper registry backup
involves taking copies of the various registry files.

 

[Nightowl]

Finally, what is a Bart PE boot CD? I will
Google for additional info.

To answer your question, I exported the entire registry with regedit as a
.reg file.

Hi Harris

I doubt you'd be able to use the .reg file you made to restore your
registry. Importing it won't delete any new entries added since you made
the export and you could end up with an absolute mess. As Pegasus said,
a .reg file isn't really much use as a backup.

However, don't despair If you had System Restore turned on you can
retrieve copies of working registry files from a restore point with a
bootable "live" CD such as Bart PE, Ultimate Boot Disk for Windows or
Knoppix and you don't have to worry about using the Recovery Console or
what type of XP installation you have. Can you get a friend to let you
use his/her computer to make one of these? I've used the following
method twice recently to rescue a friend's PC and it worked beautifully.
This is what you need to do:

Once you have your bootable CD:

1) Boot the non-working machine from the CD and use its file manager to
create a temporary working folder. The navigate to the folder System
Volume Information in your HD root directory.

This will contain one or more folders called "_restore {a lot of letters
and numbers in here}". If you have more than one, choose one that was
created before you had the problem.

2) Double-click to open your chosen folder and you should see several
subfolders with names of the form "RPnnn". Again, be sure to choose one
with Create and Modify dates before the problem arose. Open this and
you'll see another subfolder named Snapshot. This is where copies of the
registry files are stored.

3) Copy these 5 files (usually the first 5) to the working folder you
made at step 1:

_REGISTRY_MACHINE_SAM
_REGISTRY_MACHINE_SECURITY
_REGISTRY_MACHINE_SOFTWARE
_REGISTRY_MACHINE_SYSTEM
_REGISTRY_USER_.DEFAULT

In the working folder, rename the copies respectively SAM, SECURITY,
SOFTWARE, SYSTEM and DEFAULT.

4) Navigate to the folder C:\Windows\System32\config and delete the
existing files called SAM, SECURITY, SOFTWARE, SYSTEM and DEFAULT. Now
copy the new files from your working directory here. Close all windows,
shut down and remove the boot CD from the drive.

5) You should now be able to boot the PC. Once you get into Windows, I'd
strongly recommend a final step -- do a System Restore, obviously
choosing a restore point from before you had the problem (a day or two
before is good). The reason for this is that registry information on
other users won't have been replaced yet, and also System Restore will
roll back drivers etc. if one of those has caused the PC not to boot.

Good luck! Let us know how it goes Oh and P.S: once you have your
computer up and running again, may I recommend ERUNT for registry backup
and recovery? Then you'll never have to go through this again!
http://www.larshederer.homepage.t-online.de/erunt/