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How do I restore system after it breaks


Hi, I'm done with this problem. I've been over it so many times and nothing ever works.

I'm on Windows 10 64-bit Home
I have 2 drives in my PC. One is 60GB SSD, other one is 500GB HDD.

The SSD has only `C:/` on it, with Windows (System partition).
The HDD has `D:/` and `E:/` on it, which is "GAMES" and "PROGRAMS".

Yesterday I got a BSOD about memory_management and after rebooting I get a "cng.sys is corrupted" error before boot.

Correct order:
C: Windows
D: Games
E: Programs

Wrong (current) order:
C: Games
E: Programs
D: Windows

I plugged in my Windows 10 bootable USB and tried "repair pc during boot", but it couldn't fix it.
I tried "sfc /SCANNOW /OFFBOOTDIR=d: /OFFWINDIR=d:" and it found no errors.
Ugh....
I entered `diskpart` and changed C: Games to G: Games, D: Windows to C: Windows. Rebooted.
The same error again: "cng.sys corrupted or not found". Okay.
At least it's in correct order now. C: is Windows.
I run repair during boot again, nothing.
I run sfc /SCANNOW, nothing. Verification 100% complete. Windows Resource Protection could not perform the requested operation.

What do I do now? Can I just download or replace that `cng.sys` from somewhere?

/edit: Bootrec /ScanOS: Total identified Windows installations: 0.

Hi VixinG and welcome to windowssh blog.

This is a first for me, but perhaps you could download Kyhi's custom boot media, navigate to that corrupt file and replace it with a good copy from a working system?
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 blog

Then, if there are still boot issues, open Macrium Reflect (also in Kyhi's boot medai), and select the FixBoot option.

That's about all I can suggest. Perhaps others will post with some ideas.

EDIT: Have you run chkdsk on the OS drive?

Can you boot to Windows Safe Mode? If so, run sfc /scannow from and admin command prompt.

If you can't start Windows then the Macrium repair disc is worth a try.

You could try a repair install - see Repair Install Windows 10 with an In-place Upgrade

Have you tried the classic boot repair measures?

Change to the UEFI volume into the boot folder. Depending on the way Windows was installed this path maybe one of the following.
cd /d E:Boot
cd /d E:EFIMicrosoftBoot
cd /d E:ESDWindowsEFIMicrosoftBoot
Now we will need to enter three command lines to repair the BCD store. Again depending on the way Windows was installed these may not all be necessary, however
command lines are are unnecessary will not affect the outcome.


  1. bootrec /fixboot
  2. bootrec /fixmbr
  3. bootrec /rebuildbcd

If the above does not help, maybe you can boot into Windows using the Super Grub Disk? I'd give it a try...

It's also possible that the whole EFI partition is corrupted. In this case you would need to create a new one.

How do I restore system after it breaks