In a recently published support document, Microsoft has exposed a bug in Windows 10’s System Restore feature that keeps the computer from booting.
When installing a clean installation of Windows 10, setting the Restore Point, and then installing updates, you can’t go back to that original Restore Point. When you attempt to use the original Restore Point, the computer will blue screen, fail to boot, and emit a Stop error (0xc000021a).
This is a known issue in Windows 10.
During the system restore process, Windows temporarily stages the restoration of files that are in use. It then saves the information in the registry. When the computer restarts, it completes the staged operation.
In this situation, Windows restores the catalog files and stages the driver
.sys files to be restored when the computer restarts. However, when the computer restarts, Windows loads the existing drivers before it restores the later versions of the drivers. Because the driver versions do not match the versions of the restored catalog files, the restart process stops.
Microsoft provides a workaround here: You cannot restore the system to a restore point after you install a Windows 10 update