I just finished building a PC the only part left is the operating system. I pluged everything in and when I turn on the monitor it flashes to some weird menu looking screen then to a screen that says: Reboot and select proper boot device or insert boot media in selected boot device and press a key. Not my uncle just gave me a usb key which he says has windows 10 on it and that he used it for his laptop and it worked. When I plug it in nothing different happens differently than before. Please help.