When I tried to update my windows 10 to the newest version of 2004, it is failed and show Error 0x80004005. After retry a few time with no luck, I did some research and found that it is caused by corrupted BCD which in my case caused by cloning original OS from HD to SSD. To verify if you have the same symptom is to run
bcdedit /export <anyfilename>
in command prompt, if you got the error then following solution might work. Before proceed prepare bootable windows 10 installation USB or DVD then select Repair –> Troubleshoot –> Advance –> Command Prompt.
Then run following commands:
diskpart select disk 0 (replace with your system disk) select partition 0 (replace with your ESD EFI or SYSTEM partition) assign letter=z: (or whatever you prefer) exit format z: /fs:fat32 (be careful with drive letter) bcdboot C:\windows /s z: /f UEFI (replace with your windows directory and drive letter)
If you done it correctly your system should boot with no problem. You can try running the bcdedit /export command to verify, now there should be no error. Then upgrade the windows, Enjoy!