In some cases, during a clean Windows installation, upgrading to a new Windows 11, installing a new Windows 10 build, or creating a reference OS image using Sysprep, you can receive the error “The computer restarted unexpectedly or encountered an unexpected error. Windows installation cannot proceed”. When you click OK, the computer restarts, and the error window appears again, and so it goes again and again… What can you do in this case to continue Windows installation?

This problem may appear after reboot during the Windows installation (or update) and looks like this:

As I said before, if the “computer restarted unexpectedly” error occurs, neither the click on the OK button nor the restart of the Windows installation wizard helps – the error still gets looped.

To fix the problem, you don’t need to close the error message or click OK:

1. Press Shift + F10 right on the screen with the error. On some laptops, you need to use a keyboard shortcut Shift+Fn+F10, or disable the System Configuration -> Action Keys Mode = Disabled option in the BIOS settings;
2. In the command prompt that appears, start the Registry Editor using the regedit command;
   
3. In the Registry Editor, go to the reg key?HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\ChildCompletion;
4. In the right panel, find the parameter named setup.exe. Its value is likely to be 1. Change it to 3 and save the changes;
   Note. Thus we make force the Windows installer to go to the next installation phase.
   
5. Close the Registry Editor, and restart your computer by clicking OK in the error windows or using this command: shutdown -r -t 0 or wpeutil reboot

After the restart, the Windows 10 installation/update process should continue normally.

This problem is typical not only for Windows 10 and Windows 10. This solution of the interrupted installation of the operating system works well in Windows 7, Windows 8.1, and Windows Server.

Other reasons and solutions for the automatic restart problem in Windows

1. Boot from the Windows installation media;
2. Press Shift + F10 on the first install screen to open the command prompt;
3. You need to get the drive letter assigned to your Windows volume;
4. Run the command:
   diskpart
List vol
   In my example, the Windows is located on Volume 1 (according to partition size). This partition is not assigned a drive letter. Let’s assign the letter W manually:
   Assign letter=w:
exit
   
5. Now run regedit and load the registry hive HKEY_LOCAL_MACHINE\SYSTEM of your offline Windows image;
6. Select the HKEY_LOCAL_MACHINE in the Registry Editor and click the File -> Load Hive. Select the file W:\Windows\System32\Config\System
7. Set the hive name (mylocal). As a result, an offline copy of your Windows registry will be loaded in the registry editor;
8. Go to the reg key HKEY_LOCAL_MACHINE\Mylocal\Setup\Status\ChildCompletion and change the value of the setup.exe parameter to 3;
9. To save changes to the offline registry file, select File-> Unload Hive;
10. Switch to the command prompt window and restart the computer using the command: wpeutil reboot
11. The Windows installation will then continue normally.

Issue: Windows installation continues, but after 64% of Windows installation system automatically restarts and goes on loop.

Solution: burn the original Windows install image using the official Media Creation Tool (How to create a bootable UEFI USB drive with Windows 10 Setup?).

Run a clean install of Windows from a new bootable USB stick, be sure to delete all partitions on the drive you want to install Windows on (if you have your data on the drive, copy it before removing the partitions). Install Windows to the Unallocated space. Windows Installer will create all the necessary system partitions by itself (read more about system EFI and MSR partitions in Windows 10).

Also:

• Check your local disk for errors: chkdsk W: /F /R
• Disconnect all unnecessary USB devices (including the keyboard, flash drive, and mouse), disable LAN and Wi-FI network adapters (physically or in BIOS/UEFI settings)