After battling for days trying to install Windows 10 AU on my Vbox Windows 10 Guest I ended up with an unbootable machine and no where to go!
To solve the problem and to at least get back my activated copy the following worked for me:
- Download the latest Windows 10 AU update ISO from Microsoft
- In Vbox Manager Settings > Storage add downloaded ISO as an optical drive
- In Vbox Manager Settings > General > “Boot order” set new optical drive to be the 1st and Hard Disk 2nd
- In Vbox Manager start the Windows 10 machine and proceed to install the Windows 10 AU
- Depending on how badly damaged the old Windows 10 is either upgrade or go for custom new install – I did the latter.
After the new install you should end up with a fresh copy of Windows 10 and all your old stuff in Windows.old and an Activated Windows 10. Once to are happy you have everything run Disk Cleanup and remove the Previous Windows install(s) to remove Windows.old
The above approach will also work with stand-alone systems except you burn the ISO to a DVD or USB using the Windows 10 Media Creation Tool and boot from the media you create and continue from from step 5.