Win 10 System Restore Fail 0x80070091

Question:

Below about says it all.  I tried SysRes from two points, both with same failure.  

System Restore did not complete successfully. Your computer's system files and

settings were not changed.

Details:

System Restore failed while restoring the directory from the restore point.

Source: AppxStaging

Destination: %ProgramFiles%\WindowsApps

An unspecified error occurred during System Restore. (0x80070091) 

The two attempts were from: choose a different restore point>show more restore points type Backup.  I really need this function to work.  Any solutions out there?

Answer:

Renaming folder WindowsApps, reboot the system and try a system restore should cure the issue. 

1.下載下傳一個win10的iso鏡像檔案（官方原版的）
2.用ultraiso将鏡像寫入U盤(方法自己百度)
3.利用BIOS提供的啟動順序切換，從U盤啟動，耐心等待
4.選擇完語言下一步，第二個畫面左下角，點“修複計算機(R)"，點“疑難解答”，點“指令行提示符”
  依次敲入指令：
  c:
  cd "Program Files"
  md "WindowsApps-"
  xcopy "WindowsApps" "WindowsApps-" /s /e /y /h
  rd "WindowsApps"
  關閉指令行視窗，點“疑難解答”，點“系統還原”，再執行就OK了。      

I've described a solution here Windows 10 Version 1607: System restore error 0x80070091 [Fix].  

Addendum: It seems that the issue has been fixed in Windows 10 Creators Update. And there is a batch file to fix the issue. Further details may be found here: 

Windows 10: News about System restore error 0x80070091

from:https://answers.microsoft.com/en-us/windows/forum/windows_10-update/win-10-system-restore-fail-0x80070091/7f690ec3-a3da-4c14-90fd-3eb0ba83f4ac