Get USB hub, USB keyboard, USB mouse. Connect hub to cube and rest devices to hub
Boot into BIOS (hit del before logo), under “Save & Exit” menu there is “Boot Override”, USB stick should on the list, another is one with FORESEE 64Gb SSD. Select USB and hit enter, go with Windows 10 installation
Youre welcome, those technical preview key were for test pre-release of Windows 10, they don’t work any more. To make things sure please check Settings -> Update & Security -> Activation to see if Windows thinks its activated or not.