I just updated to Windows 10 today and everything was fine until one of the more recent updates (I think this is what triggered it). The keyboard is acting as though the "FN" button is being held down. When I press the FN button it lets me do the primary function of the key. For example, the 4 key will now turn up the volume unless I actually hold the FN button while pressing it. After some googling i checked the BIOS and there's nothing in there related to "action buttons". I'm on a Toshiba Satellite 775.