Windows failed to load because the system registry file is missing or corrupt.

Due to an unexpected shutdown or something else, we found that our "Windows Operation System" has failed to load into the computer. It shows an error message that is "Windows failed to load because the system registry file is missing or corrupt ".

Another clue is given by this error message that is "\Windows\System32\Config\System" file is missing or corrupt.

To resolve this issue, we have to replace that missing or corrupt file. We can replace this file using our "Windows Installation Disk".

How do we replace the windows registry file, the step-by-step process is given below.

First of all, boot your computer using the "Windows Installation Disk". After the boot process has been completed, the windows setup page will appear.

In "Windows 8 or 10" you will found the following interface.

In "Windows 7" you will found the following interface.

At this stage, press the "Shift + F10" button from your keyboard. A command prompt console should have appeared now.

Now move on to your windows installation drive. Generally, it will be the "C" drive. But sometimes the drive letter sequence which we are using in our windows operating system, that will be mismatched at this command prompt window. That means, in the windows operating system, if the windows installation drive letter is "C", then here it will appear as "E" drive or "F" drive. That's why we have to go through each possible drive letter to find out our windows installation drive. 

We will start from the "C" drive. To move on to the "C" drive, the command will be " C: ". If this drive letter is not available, then an error message "The system cannot find the path specified" will appear. On the other hand, if it is available, then the command prompt path should be changed. Just like the below:-

Now write the "dir" command and then press the "enter" button to explore this drive. If you found the "Windows, Program Files, etc" folder in this drive then it will be your windows installation drive otherwise not. The screenshot is given below:-

This way we will check using each drive letter. We have to make sure that we are in the windows installation drive. Then move on to the "Config" folder. Execute the below command:-

cd  windows\system32\config

Now command prompt path should be changed. Just like the below:-

Now we will rename the existing registry file which has been corrupted. The command will be:-

ren  system  system.bak

Now we will copy the default registry file to this location. The command will be:-

copy  regback\system  system

That's it. Now reboot your computer. It should start now.