Windows Update Breaks Windows
When you install a Windows Update or make a major change to the OS, the system often reminds you to create a restore point (assuming it doesn’t create one itself). Restore points are meant to save you from exactly the kind of mid-OS update failure that used to result in BSODs if interrupted or broken and a need for “overtop” or repair Windows installations. These could replace core files and allow the OS to boot, but also had a habit of breaking previously installed applications.
In theory, using a restore point after a Windows Update has been performed shouldn’t cause any problems — but it does. When this started, exactly, is unclear, but Microsoft has published its own guide to dealing with the problem.
According to Microsoft, triggering the bug is this simple:
1). Install a new version of Windows 10 to a fresh SSD or HDD.
2). Turn on System Protection and create a restore point.
3). Install Windows updates
4). Attempt to revert those updates.
Upon reversion, instead of a clean boot, systems will sometimes be hit with an error code: 0xc000021a. Repeated reboots will not allow the system to proceed to the Windows desktop.
Here’s Microsoft with the cause:
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.
The solution to this problem can be found here, but the short version is that you need to enter the Windows Recovery Environment (WinRE), possibly by restarting twice. Once in the WinRE, select Troubleshoot, followed by Advanced Options and More Recovery Options, and Startup Settings. Then select Restart Now. Once the machine reboots and presents you with a menu, choose “Disable Driver Signature Reinforcement.” You may need to hit F7 to select this option, according to Microsoft.
The solution to avoiding this problem is to use WinRE to handle System Restore in the first place, according to Microsoft. This seems more than a little nuts. The WinRE menu is not exactly hard to access, but it’s significantly harder to find than System Restore. This kind of error is likely to be read as an example of System Restore simply failing and corrupting the OS installation.
There’s not much we can say about the continued emergence of this sort of issue that we haven’t said before. The purpose of System Restore is to restore the system to a point in time in which it supposedly functioned better than it does at the moment. To have that process break in a manner that requires the end user to hie off in favor of another level of troubleshooting in order to restore the proper function of Microsoft’s built-in system repair tool is embarrassing at best.
PSA: Using System Restore After Windows Update Breaks Windows - ExtremeTech
