Hi, Hope someone will be able to help me (this thing is driving me crazy ! (And sorry for my broken english; I am not a native english speaker) I own a Mac Book Air, running MacOS X Sierra (and Windows 10 with bootcamp). Since yesterday, when I turn on the computer, the MacOS login page opens, and I can enter my account password without any issue (both the keyboard and trackpag work). But as soon as the desktop opens, I loose complete control of the keyboard and trackpad. The only button that remains active on the keyboard is the power on/off . I believe it's not a hardware issue. The keyboard works fine on the login page (and also works ok on Windows 10). If someone knows how to solve this problem, it would be great !!