Q: Windows 10 upgrade fail 80073B92-20009 Fusion Drive iMac

Alright, I got this error on my other half's iMac last night and it's now running Windows 10. I found this solution online and it worked for me. Give it a shot.. nice and easy to try. Good luck everyone!

Here's what finally worked for me after trying multiple times and multiple ways.

Unplug all external drives (from what I can gather from a web search this particular reference to 0x80073B92 - 0x20009 has something to do with external drives).

Go to C:\Windows\SoftwareDistributions\Download and delete anything in that folder if there is anything there.

Then go to this link http://www.microsoft.com/en-us/software-download/windows10 and click on either the 32 or 64 bit tool and then run it to update your current pc when it asks.

I will be sure to give this a try but I doubt it will help, my windows partition itself is installed on an external hard drive for me so it just wouldnt make sense to unplug it but I will try anything in hopes of updating to windows 10.

Yeah, I'd still try it because honestly I got the error with no USB drives installed at all, so I think that what actually did it was deleting those files in the software distribution folder. 

I thank you for taking the time to but unfortunately it did not work for me, same error message. What was worse is when trying to update with the setup i actually received this error code:

80070002 20016

Googled that error and didn't get any resolution except a blog suggesting using a older version of the update tool and conveniently he was nice to upload that file so i used it and spend a good 45 minutes trying to update which weirdly took longer than updating using the windows update thing. The fact that it took longer really made me think this was it but sadly it was the same train ride again, a blink of the installation screen and back to windows 8,1 with the same error code.

Unless there is any other method that doesn't involve modifying the registry or deleting the files in the software distribution folder (which i have all tried more than once previously) i think i will be stuck in windows 8.1 unless of course i manually erase the OS and install windows 10 over it and than manually install all my games back again which will take ages.

<quote>unless of course i manually erase the OS and install windows 10 over it and than manually install all my games back again which will take ages.</quote>

For those that may not know keep in mind that Microsoft requires that you upgrade first to register your device, they do not accept Windows 7 or 8 keys.  i.e. If you try removing your Win7/8 partition and installing Windows 10 fresh IT WILL NOT ACTIVATE.  There are no exceptions, customer service will not help you.

hmm… that seems like further bad news for me. Looks like I will be stuck on windows 8 permanently, don't think i'm gonna fork out 100 bucks for a new OS when majority of people are upgrading for free. Also OS X is my primary OS which i love more and more with every year, I use windows solely for games and if only game developers would support OS X by releasing their games for Macs i wouldn't even bother with windows. Hopefully Microsoft would fix issue in someway as I would like to stay updated with the latest OS for security reasons and I do believe windows 10 has improved graphics delivery using software improvements (i may be wrong don't quote me on that). Until then I'll just stick to the current OS, thanks to Frostyglitch for bringing it to my attention; appreciate it!

If im not wrong you should be able to just install windows 8.1 again and activate it with the key you have. The other choice would be to purchase a windows 10 key which costs about 100 USD i think.

Okay, so it's not the best work around but I actually got this to work finally!

First do the obvious -- make sure Windows 8.1 is fully up to date and Bootcamp 6 is installed. The only way I could update to 6 was to run the Bootcamp assistant on the Mac side and create a driver USB flash drive which I then used to update Bootcamp on Windows. The update notification in the Windows notification center was taking me nowhere.

Now -- how to upgrade to 10. Well, I run VMWare on a laptop. I never used it to boot a Bootcamp partition but in the back of my mind I was pretty sure that was a feature so I installed a copy on the iMac and sure enough. It was pretty easy to boot the Bootcamp partition with VMWare Fusion. It took a long time for Windows to sort things out and yes, Fusion wanted to install its driver set and so on but when things finally settled down I attached my Windows 10 install media on a flash drive and started it...and it actually worked! When it was all installed and I verified I could login to my account I shut the VM down and then rebooted into Windows 10 direct. If needed to reset the drivers back to the native ones but everything was not only working but I did NOT have to reinstall Bootcamp 6 -- it was still up and running from 8.1!

Again, not the best work around but I figured if I tried upgrading while in a VM then it wouldn't see the fusion drive and the theory seemed to prove out.

Worked with VMWare.

Problem now is that the virtual Windows 10 is activated and the Bootcamp windows 10 is not and can not be activated...

Okay -- that's bizarre to say the least. I was working off a Windows 8.1 Pro clean installation and it never asked for activation when upgrading to 10 off of a USB. I did NOT use the upgrade process through 8.1 -- I ran the 10 installer off the USB media. Everything seems to be running fine. Maybe it is thinking you installed Windows 10 on two different PCs? I am no Windows expert so I am lost with any additional suggestions beyond the usual MS web lookup: http://windows.microsoft.com/en-us/windows-10/why-activate-windows-10

I was actually considering doing something similar except with Parallels Desktop which was the software i was using before installing bootcamp and I still kept it on my mac in case bootcamp for some reason gave up on me or something. I did do some research about booting the through the parallels desktop but found out it was impossible so i gave up on that. After what you said however i may give VMWare a try but I don't have that software, I'm hoping they have a trial or I got to start asking friends who's got it.

As for Macs Pain with the activation issue, I had the same doubt. When I was experimenting on various ways to update to windows 10 I used my brother's MBP (since my windows 10 was installed on an external hard-drive I just plugged the drive into his mac) to boot windows and I didn't try updating through it because I couldn't. When I tried the computer claimed the copy of window 8 isn't activated and I started freaking out that I lost the license or something, switched back to my MBP and found it still activated. So, I guess windows detects that it's being run on a different PC and thus isn't activated which technically means when you activate windows you activate it for the PC you run it on instead of the drive it's installed on (which should be the right way).

I can't understand how John R. didn't experience the activating issue however, but if that method worked for him then perhaps Macs Pain you can roll back to windows 8.1 and update to windows 10 through the windows 10 installer like John R. did. Your other solution which is much much easier would be to activate through the unconventional method but I can't say too much here about that so you're going to have to google it.

So, the next day I wanted to try to activate again by phone and then talk to a support guy but somehow Windows was activated.
I didn't do anything. ^^

So the VMWare solution worked somehow.