This is what Finally helped me:
- Go Windows+R or regedit.exe on start menu
- Go to HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\Auditboot and make sure its set to zero.
- Go to HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\SysprepStatus\Cleanupstate and change value to 7 as well as GeneralizationState to 7
- Reboot.
- Try to upgrade now.
Make sure you backup your registry key because i haven't seen this solution thus far anywhere and kid f just stumbled across it clicking on things today. It worked and I was finally able to upgrade to Windows 10. And everything seems to be working fine.