I tried many different methods of attack, but on every occasion, Windows 10 Update 1709 continued to fail.
The Error Message was a follows:
|0x8007001F – 0x3000D
The installation failed in the FIRST_BOOT phase with an error during MIGRATE_DATE operation
Now, I need to point out that my Workstation is connected to a Domain, and that we use Roaming User Profiles. So, if you don’t have this scenario, the solution won’t work for you unfortunately.
Bearing in mind the Error Message, my assumption was that it had something to do with the User Profiles.
In order to get the Workstation to update, I did the following:
 Remove ALL of the Roaming Profiles from the Local Workstation using “Control Panel => Advanced System Settings => User Profiles”
Only the Administrator Account (and the Default Profile) should remain.
 Disconnect the Workstation from the Domain (make sure you know the Local Machine Administrator Password)
 Using “Regedit”, navigate to “HKLM\Software\Microsoft\Windows NT\CurrentVersion\ProfileList\” and remove any remaining Domain Accounts from the list. Don’t remove the Administrator Account (or any other local system accounts).
 Optionally, clear out any “dead” account folders from within “C:\users”.
If you try the update again, you should find that it works.
When everything is complete, you can re-join the machine to the Domain.