Error 0x80070091

Fix: Error 0x80070091 “unknown error in system recovery”

Errors are displayed during System Restore (when you try to restore your computer to an earlier point) and prevent you from performing a successful System Restore.

This error is caused by some problem with the WindowsApps folder. Error code 0x80070091 basically means that the destination directory is not empty. So during System Restore, there is a folder in WindowsApps that is supposed to be empty but not. This could be caused by an antivirus program blocking the process or because of the Sync Settings. But since this happened with the latest versions of Windows 10, we cannot be sure exactly what is causing the problem.

Lỗi 0x80070091

Method 1: Uninstall the anti-virus application

The first thing you should do is uninstall any antivirus you may have on your computer. Antivirus applications are known to interfere with this process and prevent your computer from performing a successful system restore.

While you can uninstall the antivirus from the Windows Programs and Features window, often getting rid of the leftover files can cause problems even if you uninstall the anti- withdraw. So it is better to use a third-party tool called Revo Uninstaller, which will not only delete the application but also help you to delete the remaining files.

  1. Go here and download Revo Uninstaller. You can download the free version, which will be enough.
  2. Install Revo Uninstaller by running the exe file you just downloaded. Just follow the instructions on the screen
  3. Once installed, run Revo Uninstaller
  4. Locate the anti-virus program you want to uninstall and select it
  5. Click Uninstall . Select Yes if Revo asks for confirmation. Follow any additional on-screen instructions you may see
  6. After uninstalling, you will see a new window in Revo. Click Advanced and select Scan
  7. Wait for the scan to finish.
  8. Revo will now show you all the redundant files it finds
  9. Make sure all files are selected (if they are already selected then choose Select All ) and press Delete
  10. Click Next.
  11. Revo will show you a list of registry files again, make sure all of them are selected (if they arent then choose Select All ) and hit Delete
  12. Click Finish

Now try a system restore to see if the problem gets solved.

Method 2: Using Windows Recovery Environment

Performing a system restore from the Windows Recovery Environment can also be proven to be successful especially if it is interrupted by some other program.

  1. Press the Windows key once
  2. Select the power option
  3. Press and hold SHIFT and select Restart

Once the computer reboots, you will be taken to the Windows Recovery Environment screen with the options Continue, Troubleshoot and Shut down your computer. You can navigate to the System Restore option from this environment by following the steps given

  1. Click Troubleshoot
  2. Click Advanced Options
  3. Select System Restore

Now the computer will ask you to choose a system restore point. Select the Restore Point you want to go to and follow the on-screen instructions from there.

Method 3: Recover the system from Safe Mode

Safe Mode is a mode for Windows that runs only in a minimal interface with only required programs. This way you can ensure that no other program like antiviruses is interfering with your System Restore.

  1. Press the Windows key once
  2. Select the power option
  3. Press and hold SHIFT and select Restart
  4. Click Troubleshoot
  5. Click Advanced Options
  6. Select Startup Options
  7. Select Restart
  8. Your system will now reboot and will give you many options to choose from
  9. Press F4 to run Safe Mode

Now your computer will enter Safe Mode, which just means the essential programs will be running so there won’t be any interruptions. Now perform a System Restore from this Safe Mode by performing the steps given below

  1. Hold Windows key and press R
  2. Type rstrui. Exe and press Enter
  3. Click Next
  4. Now select the restore point you want to enter
  5. Click Next and select Finish

Now wait for the restore to complete.

Method 4: Change WindowsApps permissions from Safe Mode

The problem can be solved by deleting or renaming the WindowsApps folder. But the WindowsApps folder cannot be accessed, and therefore, modified through my computer or by any other conventional means. So in the process, you’ll use Command Prompt to run some commands that will allow you to access the WindowsApps folder so you can rename the WindowsApps folder.

  1. Press the Windows key once
  2. Select the power option
  3. Press and hold SHIFT and select Restart
  4. Click Troubleshoot
  5. Click Advanced Options
  6. Select Startup Options
  7. Select Restart
  8. Your system will now reboot and will give you many options to choose from
  9. Press F4 to run Safe Mode

Once in Safe Mode, you need to follow the steps given below

  1. Hold Windows key and press X
  2. Select Command Prompt (Admin)
  3. Enter the lines given below and press Enter after each

cd C: Program Files

takeown / f WindowsApps / r / d Y

icacls WindowsApps / grant “% USERDOMAIN% % USERNAME%” 🙁 F) / t

attrib WindowsApps -h

rename WindowsApps WindowsApps.old

Basically on the first line, you’ll get to the folder that contains the WindowsApps folder. Once you’re there, only then will you be able to make the change.

In the second line, you are taking ownership of the WindowsApps folder as the current user. By taking ownership of WindowApps, you also own all of its content. You will have to wait a while after running this command.

In the third line, you are giving full control over the folders and, therefore, the WindowsApps folder. This is necessary because you need to rename the WindowsApps folder. You should see the message “Successfully processed xxxxx files: Failed to process x files”. If all goes well, you will not see any failed file processing.

In the fourth line, you are making the WindowsApps folder not hidden. Because if it is hidden, you will not be able to rename the folder

And, in the last line, just rename the WindowsApps folder to WindowsApps.old. You can name anything, but using old words will help you remember which folder is renamed.

Once this is done, you should be able to run System Restore successfully. After completing the above steps, restart your computer and try running System Restore again.