regfixup

This tool will help you fix broken registry hives.

Examples:

• BAD_SYSTEM_CONFIG_INFO blue screen
• ERROR_BADDB when using DISM/after a bad Windows Update

Downloads

Releases page has the latest Windows build. For other platforms see "Build instructions"

How to use

regfixup 1.1 (https://github.com/helloryuko/regfixup)
fix broken registry hives with desynchronized sequence numbers or wrong checksum

usage: regfixup [hive file location]

optional parameters:
  -h  show this help message
  -p  prefer primary sequence number
  -s  prefer secondary sequence number
  -c  only recalculate checksum

return codes:
  0   fixup successful or not required
  1   can't open file
  2   file isn't a regfile
  3   invalid parameters

I just want to fix my BSOD, how?

Find the broken registry hive

1. Boot into a Windows installation medium
2. Choose language and click "Repair options"
3. Click "Command Prompt"
4. Enter dism /cleanup-image /restorehealth /image:C:, where C: is the disk with your broken Windows installation

• If you have an error about scratch partition, create a folder on some disk with mkdir C:\somefolder and add a /scratchdir:C:\somefolder parameter to DISM

5. The check should fail and it will output "The DISM log file can be found at ..."
6. Enter notepad <path to log file> without the brackets
7. Search for "ERROR_BADDB" in the file
8. You will find a string that looks something like this: Failed to load offline SOMETHING hive. The word instead SOMETHIHNG is your hive.

Fix the registry hive

!!! WARNING !!! Do a backup of your C:\Windows\System32\config folder before proceeding! Don't blame me if something broke and you don't have a backup :)

1. Somehow obtain a copy of regfixup. You can drop it into your pendrive besides your Windows installer
2. Enter X:\regfixup.exe C:\Windows\System32\config\YOUR_HIVE_NAME, where YOUR_HIVE_NAME is your hive name (duh)
3. Choose either primary or secondary sequence
4. Reboot, you can do that with wpeutil reboot command

Build instructions

CMake (any platform)

0. Download any C compiler and CMake
1. Create build folder
2. cd build
3. cmake ..
4. cmake --build .

Windows

0. Download Visual Studio
1. Open "Developer Command Prompt"
2. cl regfixup.c

Linux/macOS

0. Install either clang or gcc
1. Open terminal
2. clang regfixup.c -o regfixup or gcc regfixup.c -o regfixup