Use the BIOS repair tool.
Here is the download link:http://www.xidulaptop.com/download/details-12-17.html

1.Unzip and open folder”KN5_XIDU_V113_BIOS_Release_20191105A”
2.Click ”File”button on the left ,then click “open windows PowerShell as administrator”.
3.Input ”cmd” in the blue pop up window,then press the Enter key
4.After it is done,input “flash.bat”,press the Enter key again.
5.When it is over,pls input “fp”,then press Tab key,choose “FPTW64.exe”.
Press Spacebar,input”-f” then press Spacebar again,press Tab choose KN5V133_XIDU.rom ,press the Enter key again.

7. When it shows “FPT Operation Successfully”,just restart the window,no need to close the window.That's all.