Hi, thanks for your reply. I tried all things above, including a clean install of windows 10. A clean install works perfectly, but I cannot activate if I not upgrade from my windows 8.1 installation...

Hi, I am trying to upgrade one of my desktops from Windows 8.1 to Windows 10 build 10240, but I am always receiving the error that Windows 10 Installation has failed. I tried to upgrade my ultrabook...