This afternoon, I rebuilt a pc with Windows 8. That is not much problems about that, however, after I finished the process of rebuilding and trying to upgrade for Windows 10. I downloaded Windows 10 Upgrade assistant. It helped me to download the windows 10 installation files. However, the 1st attempt is failed after all files are installed, but it said more one of components are failed to configure. And it restored to Windows 7. In 2nd attempt, I unplugged all USB external devices, such as printers and scanners. Then it upgraded successfully. If you faced the similar errors, maybe you can try this method!