Fix Windows 10 can't be restored after you install an update
Windows 10 administrators who install Windows 10 on a computer may receive a stop error when they attempt to restore the system after installing updates.
Updates may be installed automatically or manually after Windows 10 is installed on a device. These updates bring the operating system to the newest version and they may patch security issues and introduce other improvements.
Windows 10 users who run into issues after update installation may use System Restore to restore the system to an earlier version.
Microsoft notes that it may happen that Windows 10 cannot be restored to an earlier version and that users receive the Stop error (0xc000021a) instead.
Consider the following scenario:
- You install Windows 10 on a clean computer.
- You turn on system protection, and then create a system restore point that is named "R1."
- You install one or more Windows 10 updates.
- After the updates have finished installing, you restore the system to the "R1" restore point.
In this scenario, the system is not restored to the "R1" restore point. Instead, the computer experiences a Stop error (0xc000021a). You restart the computer, but the system cannot return to the Windows desktop.
Windows stages the restoration of files that are in use during a system restore process. The information is saved to the Windows Registry and the restoration completes on the next start of the PC.
In this particular situation, Windows 10 loads the current drivers before restoration and that leads to a driver mismatch and the stop error. The restoration process is stopped because of that.
Microsoft proposes two fixes for the issue: the first explains how systems may be recovered that failed to start while the second suggests an option to avoid the issue completely.
If Windows 10 fails to start during recovery
Administrators need to enter the Windows Recovery Environment to fix the issue. The environment should be loaded automatically after several failed restarts.
- Select Troubleshoot > Advanced Options > More Recovery Options > Startup Settings > Restart Now.
- The list of startup options is displayed. Select Disable Driver signature enforcement (F7).
- Follow the instructions. Windows should be able to resume the system restore process and finalize it this time.
To avoid the issue altogether
Microsoft suggests that system restore is run using the Windows Recovery Environment and not through the Settings application.
- Use Windows-I to open the Settings application.
- Go to Update & Security > Recovery.
- Select Restart Now under Advanced Settings.
- When Windows restarts, select Troubleshoot > Advanced Options > System Restore.
- Follow the instructions to select a system restore point and restore the system.