This vid contains tips that help Fix error code 0x80070091 while trying to delete some shared stuff or, restore your Windows.
Solution 1: Right click the drive/disk that the target folder / other item is on Click Properties. Select Tools. In "Error checking", click Check. Solution 2: delete the unwanted item in Windows Safe Mode. Solution 3: Try renaming the target item, such as $Recycle.Bin > follow > empty Recycle. Solution 4: back up your personal data and format the drive that the target folder.
If you can't transfer data from external hard drive to local disk, or perform a system restore
step 1: run the below cmd code as the admin user chkdsk /f /r X:( drive letter for external hard drive) step 2: follow... restart your system