How to fix Windows 10 Registry With bootable Install USB?

Question

After an update on the 16th/17th, my Windows 10 computer failed to boot. Long story short, I tried a bunch of things and it turns out that the registry got messed up by the update. It now hits BSOD with error "Critical Process Died" after a few seconds of loading.

The issue at hand hasn't been addressed for me, and the way to "fix" it, according to Microsoft, is to completely re-install.

However, by replacing a few of my registry files (namely SYSTEM), I can get the computer to at least try to boot up before it hits the BSOD, and critical process dies. This indicates to me that it is a small error in a badly tested update that was pushed too soon, and that it CAN be fixed somewhere in the registry.

I think that the root cause here is that a file besides SYSTEM (from the bad update) has taken hold somewhere else in the registry (or updater). Every time you boot up, it tries to run the bad update, and breaks the SYSTEM registry file. This, in turn, kills the critical process and you hit the BSOD.

I asked for help on the Microsoft website, but it's all just a bunch of generic responses that don't actually address the problem, usually boiling down to "wipe your hard drive and start over with a new install." Ridiculous, and I'd rather spend half a week messing with the registry to try to fix this, than start over with everything.

Yes, I backed up my important personal files.

Longer story:

When I tried to boot up, it was stuck in a reboot loop where it would continually fail to repair itself.

I spent the day trying to fix it, but I couldn't find anything that worked. I became stuck with "The operating system couldn't be loaded because the system registry file is missing or contains errors.

Error Code 0x0000225 "

Here's what I tried initially that did NOT work (And made it worse):

• Attempting to repair the BCD (Access denied)
• Disabling automatic recovery mode in the BCD (Which now means I can't -access command prompt from the native system, and I also can't reset the setting)
• chkdsk (No errors found)
• sfc /scannow (No errors found)
• DISM /Online /Cleanup-Image /RestoreHealth (Various issues, highlighted below)

DISM was the most promising, but I can't get it to run. My only way to work on the system is to boot into the installation USB, and navigate to the command prompt. Whenever I run DISM, it errors "Error 50 DISM does not support servicing Windows PE..." and if I remove /Online with /Source:X:\Windows I get "Error: 87 the cleanup-image option is unknown". There are other errors, but all in all it just flat out does not work. Even if it did, I suspect it would find nothing. The files are not corrupted, but contain errors.

I don't have an option to do a system reset keeping personal data, because I can't do anything with the native system. The USB system does not have the option.

I'd like to at least try using the DISM tool, but I can't get it to work from the install USB.

Here's what I did to edit the registry, which has made a difference:

I made a backup of C:\Windows\System32\config*

I deleted all files and subfolders in config\

I copied X:\Windows\System32\config* to C:\Windows\System32\config*

Shut off computer, and restarted. Windows begins to boot. After loading a few seconds, it hits a blue screen with the error: "CRITICAL PROCESS DIED"

I then replaced the DRIVERS file I copied into C:\Windows\System32\config\ with my old DRIVERS file.

Reboot, same error.

I enabled boot logging, and tried again. Also note that I DID attempt to use the auto fix from the bootable install disk, but it still fails.

Here are the contents of the boot log:

Version 10.0 (Build 17763)

BOOTLOG_LOADED \SystemRoot\system32\ntoskrnl.exe

BOOTLOG_LOADED \SystemRoot\system32\hal.dll

BOOTLOG_LOADED \SystemRoot\system32\kd.dll

BOOTLOG_LOADED \SystemRoot\system32\mcupdate_GenuineIntel.dll

BOOTLOG_LOADED \SystemRoot\system32\drivers\msrpc.sys

Maybe this will give some insight into the issue at hand. I assume that the process dies as msrpc.sys attempts to run (and may be the process that dies).

I reverted the config folder on C back to the original, then only replaced the SYSTEM file. The system will attempt to boot, fail because critical process died, but NOW, it "gathers information" and reboots. After the reboot, the system file is broken again.

So to recap, here's where I am now:

Computer can try to boot, but hits BSOD with "Critical Process Died", it "gathers information" and reboots. After the reboot, the system file is broken again.

Sort of the icing on the cake is that windows used to have automatic backups of the registry to prevent this very situation... Which for some stupid reason they discontinued partway into Windows 10. That would have saved my computer and me a solid two days already.

Any help is appreciated!