A few months ago I built myself an HTPC based on a NUC (Celeron processor) and loaded Ubuntu and XBMC on it. I controlled it with a Logitech K400 keyboard. It was working great until yesterday when the keyboard stopped working. I tried rebooting the NUC a few times, tried changing batteries in the keyboard, and tried putting the dongle in the other USB jack. Then I tried using a USB mouse from my desktop instead. Nothing is working. I cannot see a cursor on the screen. I'm running out of ideas! Is there anything else I can try? Do I need to re-install the OS?