I have mma 10.4 installed on a PC with windows 10 and one with windows 8.1 In mma, on the PC with windows 10, if I hold down a key, then nothing happens. Nothing at all. I can hold the key down for a looooong time, and nothing happens. But when I release the key, then mma shows all of the keystrokes that have been entered. I don't have this problem in mma on the PC with windows 8.1, nor do I have this problem with any other programs on my Windows 10 PC. Any suggestions?