This is a problem I've been facing ever since I reformatted the system. I'm using wireless keyboard and when ever the machine is turned on, it wouldn't respond for the keyboard or mouse at the login screen. I have to force shut down and turn it on back to make it recognize. The second time works like a charm. Sometimes audio won't work for the first time but force restart solves it. I don't know why but I did install all the drivers. Could anyone help me out here.