升级Windows 10 16193回退后，安装系统遇0xc0e90002错误解决办法

1. prepare a USB flash drive (with capacity less than or equal to 32GB)
2. format it with FAT32 file system
3. download the EFI Shell, Shell_Full.efi, from Github
x64 system (if you're using 64bit OS)
x86 system (if you're using 32bit OS)
4. rename the filename of the EFI Shell
rename it from Shell_Full.efi to bootx64.efi  (if you're using 64bit OS)
rename it from Shell_Full.efi to bootIa32.efi (if you're using 32bit OS)
5. copy it to \EFI\Boot\ folder of the USB flash drive
6. launch the BIOS SETUP to disable "Secure Boot", save the changes and exit the BIOS SETUP
7. boot from the USB flash drive
8. show EFI variables
 dmpstore -b *Revoke* [Enter]
9. you'll see "Revoke" information
10. delete the "Revoke" information (in my case, I needed to delete two EFI variables below)
dmpstore -d RevokeSiSPolicySigners [Enter]
    dmpstore -d RevokeSiPolicyVersion  [Enter]
11. shut down the computer from the EFI Shell
  reset -s [Enter]
12. (optional) launch the BIOS SETUP to enable "Secure Boot", save the changes and exit the BIOS SETUP