I was using my wife's PC as mine had gone for repair. I had installed ubuntu and now she needs windows 10 back on it, as she is totally blank with ubuntu and the command line. So, I have just got a bootable windows 10 64 bit USB drive. Now how do I format this ubuntu completely and install windows 10 fresh ? Pressing F8 or F10 or F12, doesnt open the bootable option. How do I tell the PC to boot to USB ?