You probably have the same problem I had, which is a slightly non-standard disk layout. Windows Update will fail without producing any meaningful diagnostics. It took me a lot of time and much effort to finally get past that and get my system working.
Things to check:
Are you UEFI booting an MBR disk? It works, but Windows Setup will fail in future upgrades.
Do you have all the correct and required partitions? If you don't have the right partitions (OEM, EFI) of the right size, Windows Setup will again fail with cryptic errors, none of which say "your partitions are wrong".
> Do you have all the correct and required partitions? If you don't have the right partitions (OEM, EFI) of the right size, Windows Setup will again fail with cryptic errors, none of which say "your partitions are wrong".
Worth pointing out you don't have to be sharing the drive with another OS to get this situation. I had a system which I upgraded from 7 -> 8.1 -> 10. My linux install and bootloader are on a totally separate drive. This left the drive with:
* 100mb system reserved partition (unused, created by win 7 installer)
* 250gb C: partition
* 400mb system reserved partition (created by 8.1 or 10 update, actually used)
Then I used the Samsung tool to copy to my new ssd and ended up with a 100mb system reserved partition and a 1tb c: drive. But the 1709 update tried to unpack the >100mb update into the too small system reserved partition and failed in a loop
Sure. My system disk was Windows only, but I go to pretty extreme lengths to avoid reinstalling Windows. So after my latest system upgrade I had a UEFI system running off a MBR disk and some bad partitioning. This was a source for much amusement...Window Setup would fail without explaining why, mbr2gpt would fail without explaining why, the BCD tools behaved badly, the Windows 10 recovery environment wouldn't work, etc.
Gradually, with much trial and error, I managed to work through each problem, until I wound up with a mostly correct GPT disk and a fully functioning system. It's now successfully applied several updates correctly, where previously it would get to 99%, fail, then roll back, only to try again the next day. As a side effect, I now know more about Windows 10 booting, the BCD, and GPT than I ever wanted to.
The only "problem" I have now is an unused old boot partition that I'm frankly terrified to try to remove, since it'll renumber all of the partitions and cause some problems. I'm relatively sure I know how to fix it, but it's too risky to contemplate right now.
Things to check:
Are you UEFI booting an MBR disk? It works, but Windows Setup will fail in future upgrades.
Do you have all the correct and required partitions? If you don't have the right partitions (OEM, EFI) of the right size, Windows Setup will again fail with cryptic errors, none of which say "your partitions are wrong".