For a while now my work laptop was trying to update to Windows 10’s latest build (2004) but kept failing when almost finished.
You can manually go through the log files (located mostly at C:\windows\panther\ ). See below link to KB928901 for the complete list.
https://support.microsoft.com/en-us/help/928901/log-files-that-are-created-when-you-upgrade-to-a-new-version-of-window
However, I recommend using the much easier SetupDiag tool, also from Microsoft. Download the tool from the below link and save it to a folder Tools on your C: drive (for convenience).
https://docs.microsoft.com/en-us/windows/deployment/upgrade/setupdiag
From version 2004 onwards the tool should run automatically after failed setup, but it didn’t in my case, or did not show the relevant information anyway.
When I manually opened a command prompt (CMD) with administrative privileges and started “setupdiag” it showed me the reason for failing the update.
cd c:\tools
setupdiagI had to scroll down a little bit in the output and found this:
Error: SetupDiag reports abrupt down-level failure. Last Operation: Finalize Error: 0x80004005 – 0x60016 LogEntry: 2020-07-21 19:00:10, Error SP Operation failed: Update Boot Code. Error: 0x80004005[gle=0x000000b7]
Specifically “update boot code” showed me the problem had something to do with the special EFI partition where the boot files reside (in case of UEFI boot, as I am using).
When I had a look at my partition layout with disk management, I saw a EFI partition (100MB, a bit small) and 2 Recovery partitions (+/- 500MB each) and some unused space in between them. A strange partition layout, I maybe suspect Acronis to be the reason for this.
Warning: What I did next is for advanced users, because it will make Windows stop from booting if not done correctly.
This is only for UEFI boot, not for Legacy boot.
– I deleted the recovery partitions, deleted the EFI boot partition.
– I made a new EFI boot partition and copied the bootfiles to it.
diskpart
select disk 0
create partition efi
format quick fs=fat32
exit
bcdboot C:\windows– I used a free partition manager tool to expand/move my C partition so the unused space between the partitions was gone.
I tried the Windows Build update again and was successful!