Okay here is what i did in order to upgrade to win 10 and later do a clean install and register without issues:
> Upgraded "dirty" by keeping my files and settings using Windows Media Creation Tool:
https://www.microsoft.com/en-us/software-download/windows10
> Used macrium reflect free to backup and create an image of drive.
> Used Windows Media Creation Tool again to create a bootable USB installation of win10 pro or "DVD" which ever you prefer.
> Booted up USB to make a clean install. Choose Advanced Install and format only once big partition of the drive. Note! leave all other small partitions intact of the drive.
-----> "Important" while trying to make a clean install use "Skip" and don't insert ANY keys!! You will have to do this a second time while installing and choose "Skip" again. The copy of win10 Will get registered on itself once its booted!!
> Booted up once finished Clean Install and updated everything through windows update. You may need to reboot as you might have some errors on updates.
> Installed macrium reflect free again and done an image backup of my clean install. That's it!!
Now restored back to my dirty update using macrium reflect until i get my files and stuff that i want stored on another drive.
Hope this helps you all, enjoy!!