
Advanced Fix: Extracting a Clean Registry Hive from Windows 11 USB
Since your RegBack folder is empty and you don't have System Restore points, we can extract a brand-new, clean SYSTEM registry file directly from your Windows 11 Installation USB media. This will allow your PC to boot up so you can save your data and apps.
Step 1: Boot from the Windows 11 USB
1. Insert your Windows 11 installation USB drive into the corrupted PC.
2. Restart the PC and press the boot menu key (usually F12, F11, F8, or Esc depending on your motherboard) to boot from the USB.
3. When the Windows Setup screen appears (where you select language and keyboard), press Shift + F10 on your keyboard. This will open the black Command Prompt window.
Step 2: Identify Your Drive Letters
In the recovery environment, drive letters often change. We need to find your actual Windows drive and your USB drive.
1. Type C: and press Enter, then type dir and press Enter.
* Look for the Windows and Users folders. If you see them, C: is your Windows drive. If not, try D:, E:, etc., until you find it.
* For the rest of this guide, we assume C: is your Windows drive.
2. Find your USB drive letter by typing dir D:\sources\boot.wim or dir E:\sources\boot.wim.
* Once it successfully finds the file, note that letter. For the rest of this guide, we assume D: is your USB drive.
Step 3: Mount the Clean Image and Replace the File
Now we will use the DISM tool to temporarily unpack a clean Windows image into a temporary folder, copy the fresh SYSTEM registry hive, and replace your broken one.
Run the following commands one by one, pressing Enter after each:
1. Create a temporary folder on your hard drive:
md C:\scratch
2. Mount (unpack) the clean boot image from the USB into that folder:
dism /mount-wim /wimfile

:\sources\boot.wim /index:1 /mountdir:C:\scratch
(Wait a few moments for the progress bar to reach 100% and show "The operation completed successfully")
3. Create a safety backup of your current broken registry folder (just in case):
md C:\Windows\System32\config\broken-reg
copy C:\Windows\System32\config\* C:\Windows\System32\config\broken-reg\
4. Copy the fresh, clean SYSTEM file from the unpacked USB image into your actual Windows registry folder:
copy C:\scratch\Windows\System32\config\SYSTEM C:\Windows\System32\config\SYSTEM
(Type Y to confirm and overwrite the existing broken file)
5. Unmount and clean up the temporary directory:
dism /unmount-wim /mountdir:C:\scratch /discard
rd C:\scratch
Step 4: Reboot Your PC
Close the Command Prompt by typing:
exit
Now click the X on the Windows Setup window to cancel the installation. The PC will reboot. Unplug the USB drive and let it boot into your normal Windows 11.

What to expect after booting:
Since we replaced the SYSTEM hive with a generic factory one, your personal files and installed programs will still be safely on the disk, but Windows might "forget" some hardware drivers (like Wi-Fi, audio, or graphics card). Once you are back on your desktop, make sure to copy your important files to an external drive first, and then run Windows Update or your manufacturer's driver utility to re-install any missing drivers.