By default, Windows 10 backs up the registry to the RegBack folder when the computer restarts, and creates a RegIdleBackup task to manage subsequent backups. Windows stores the task information in the Scheduled Task Library, in the Microsoft\Windows\Registry folder.
Starting in Windows 10 version 1803, Windows no longer automatically backs up the system registry to the RegBack folder. If you browse to to the \Windows\System32\config\RegBack folder in Windows Explorer, you will still see each registry hive, but each file is 0kb in size.
This change is by design, and is intended to help reduce the overall disk footprint size of Windows 10. To recover a system with a corrupt registry hive, Microsoft recommends that you use a system restore point.
If you have to use the legacy backup behavior, you can re-enable it using the method in this tutorial.
This tutorial will show you how to enable Windows 10 to automatically backup of the system registry to the RegBack folder when the computer restarts.