Getting the error
We Couldn't install windows 10
0x800707E7 - 0X3000D
The installation failed in the FIRST_BOOT phase with an error during MIGRATE_DATE operation
if you look in C:\$Windows.~BT\Sources\Panther\setuperr.log
you will see some clues
look for c:\users that dont exists - remove them and also in registry
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
also it might be a folder that cannot be moved as the update deletes and re-creates user folders
noticed that
[userdir]\AppDataLocal\NPE was showing it cannot be deleted
this gets created on every reboot, so need to stop it
remove everything down from
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WMI\Autologger\NPETraceSession]
and the folder
[userdir]\AppDataLocal\NPE
reboot and check its gone
re-run your upgrade