Technical

Windows 10 1809 Update Error 0x800F081F

Remove “Windows Developer Mode“ first.

Background

I’m upgrading all my Windows computers to the latest major Windows build 1809 (october update). 3 upgraded OK, but my laptop didn’t.

I used the media creation tool to create a USB, which I’ve used to upgrade each of them.

The Error

The installer went through its normal process OK, and started the actual upgrade. I walked away at this point, because I had better things to do than watch the line go across the screen.

When it restarted, I had this error: 

0x800F081F - 0x20003
The installation failed in the SAFE_OS phase with an error during INSTALL_UPDATES operation

We couldn't install Windows 10 - 0x800F081F

At this point, I rebooted my computer and tried again - with the same result.

As an aside, as much as Microsoft can produce some pretty poor software at times, my experiences with the Windows updater have been very good. OK, it hasn’t always worked, which isn’t fantastic. But even if terrible and horrible errors occur (and I’ve seen a few doosies), it managed to put things back the way they were and leave you with a usable system, albeit unupgraded.

The place to look for reasons why the update failed are: c:\windows\panther\setuperr.log and c:\windows\panther\setupact.log. You might need a bit of technical knowledge (or a friend who can decypher the programmer jargon), but there’s a stack of information in there.

But I couldn’t see anything which stuck out at me. Which left me a bit stuck.

The Solution

So I tried searching the error code 0x800F081F.

And someone’s YouTube video appeared.

Normally I avoid videos like the plague (it takes 15 minutes watching them to get the same information I could read in 2). But this one was titled with the exact error I was trying to fix, and it only went for 2 minutes.

Turns out you cannot upgrade with the optional feature Windows Developer Mode installed.

So, Start -> search for Manage Optional Features -> remove Windows Developer Mode.

And this time the upgrade worked fine!

Thanks Gone!

Conclusion

No idea why, but you can’t upgrade to Windows 10 October update (1809) with Windows Developer Mode installed. Remove it first and you should be OK.