no need to use assistive route just
Generate a genuine ticket with
gatherosstate.exe from your downloaded Windows 10 & fresh install
or as mentioned for home & pro users use migration tool
Download your original w10 ISO which is suitable for the upgrade path. I.E. W7(SP1) Ultimate upgrades to w10 pro.
Follow these steps
closely
1 check OS activated (optional)
1.1 Install all necessary drivers before the next step otherwise your hardware id may not match the Windows 10 hardware id.
2. Generate a genuine ticket of your installation by:
2.1 Copy gatherosstate.exe from your downloaded Windows 10 10240/10586/14393/15063/16299 ISO to your installation which should be upgraded.
2.2 Run it on your activated and validated Windows. It'll output GenuineTicket.xml. Save this on a USB thumb drive or something.
2.3 Then do a fresh install with your suitable w10 ISO, skip to enter key at setup procedure.
2.4 Once it's installed make sure your internet connection is DISABLED/do not enable the internet connection! Reboot w10.
2.5. Copy GenuineTicket.xml to C:\ProgramData\Microsoft\Windows\ClipSVC\GenuineTicket\ of your w10 installation
and reboot again.
2.6.
Connect online
, it should activate.
I just summarized this.
This method does NOT require the annoying upgrade process itself and avoids issues!
When doing another clean install in the future just install w10 again while being ONLINE. It activates again.
thanks to original op you know who you are
personally did this lots of times & never failed me